Calculation of a cavitation device for industrial water treatment

Abstract

Relevance. Currently, the issue of preventing pollution of the hydrosphere by industrial wastewater, the use of new effective technologies for industrial water purification and its reuse in production is extremely acute. In this regard, the urgent tasks are the search and implementation of new methods of water treatment: innovative technologies, disinfection and desalination of water, methods of its reuse.Methods. The article proposes a new technology for water treatment – the cavitation effect on the flow is enhanced by the shock effect of a pressure surge, which makes it possible to suppress the vital activity of microorganisms in the water. On the basis of the developed workflow, its mathematical model and the author’s methodology, calculations were made for three hydrodynamic cavitation devices with a pressure jump in order to disintegrate sulfate-reducing bacteria in industrial waters.Results. In accordance with the terms of reference (nominal fluid flow Q, nominal absolute pressure before installation P1, allowable pressure drop on the device ΔP, nominal fluid temperature t, physical properties of the medium) based on the proposed working process of a hydrodynamic cavitation device that forms a supersonic flow with a transition to subsonic through a pressure jump, an appropriate mathematical model and an adequate technique, the regime and geometric parameters of three pilot samples of hydrodynamic cavitation devices designed to destructurize sulfate-reducing bacteria in industrial waters were calculated. In order to form a supersonic flow in the installation under sufficiently strict conditions for ensuring permissible pressure drops, a nozzle was profiled with a minimum drag coefficient along the Vitashinsky curve. Industrial testing of cavitation devices showed good convergence of theoretical and experimental data: the suppression of bacteria was carried out by 80–100%.