ULTRASOUND COAGULATION IN VENTURI SCRUBBERS: FEATURES OF IMPLEMENTATION AND EFFICIENCY OF APPLICATION

• Published in: Izvestiâ Tomskogo politehničeskogo universiteta. Inžiniring georesursov Vol. 331; no. 5; pp. 128 - 139
• Main Authors: Vladimir N. Khmelev, Andrey V. Shalunov, Sergey N. Tsyganok, Viktor A. Nesterov
• Format: Journal Article
• Language: Russian
• Published: Tomsk Polytechnic University 01.05.2020
• Subjects: acoustic field; ash particle; gas purification; sound pressure; ultrasonic coagulation; venturi scrubber
• ISSN: 2500-1019; 2413-1830
• DOI: 10.18799/24131830/2020/5/2643

The relevance of the research is caused by environmental requirements for flue gases from coal-fired TPPs and TPPs. Environmental requirements are ensured by ultrasonic coagulation of solid ash particles with liquid droplets, which is realized in devices for wet gas purification – in Venturi scrubbers. The main aimof the research is to increase the efficiency of Venturi scrubbers for wet gas purification by improving the conditions for absorption of ash particles by liquid droplets in acoustic fields created by ultrasonic coagulation. Objects: processes of ultrasonic coagulation of ash particles with drops of irrigated liquid in a Venturi scrubber. Methods. Theoretical methods were based on the numerical solution of equations describing the motion of a gas-dispersed flow in a Venturi scrubber and the coagulation of ash particles in an acoustic field. Experimental results were obtained during industrial tests at the boiler unit BKZ-220-100F CHP, operating on the coal of the Kharanorsk deposit, according to the approved methodology RD 153-34.1-27.301-2001. Results.The authors developed the physical and mathematical model that describes the gas-dispersed flow motion in a scrubber and the interaction of dispersed particles with each other in an acoustic field. The model made it possible to calculate the efficiency of gas purification under various conditions and determine the optimal modes of ultrasonic exposure: the sound pressure level is not less than 145 dB, the frequency is 22 kHz, the exposure zone in the entire volume of the Venturi pipe, the direction of the acoustic field is perpendicular to the gas flow. The maximum efficiency of ash particles coagulation in the Venturi scrubbers and the maximum degree of purification of flue gases were the criteria of optimality. The created ultrasonic equipment was tested at the BKZ-220-100F CHP unit in an ash collecting unit: the concentration of ash particles in the exhaust gases in the acoustic field decreases by four or more times (efficiency not less than 98%), the percentage of ash particles (size less than 5 microns) is reduced to 15 times.