INDUSTRIAL TESTING OF A WET TYPE CENTRIFUGAL-VORTEX GAS CLEANING INSTALLATION AT "RUSAL ACHINSK" JSC
The PURPOSE of the paper is determination of the efficiency of dust cleaning by a wet scrubber as the third gas purification stage of “RUSAL Achinsk” JSC sintering furnaces with the use of a sub-slurry water (SSW) as a gas-cleaning solution and setting of optimal operation conditions for the equipment. METHODS. Pilot-industrial tests have been carried out on two wet gas-cleaning installations of centrifugal-vortex type with the capacity of 200 thous. m3/h. The installation includes two scrubbers having dispersing lattices with guide blades, two droplet separators and a system of gas-cleaning solution feeding and subsequent collection of the spent solution in the scrubber bottom. Two scrubbers connected in parallel represent the third gas cleaning stage of the sintering furnace. RESULTS. When the consumption of the sub-slurry water is 0.3-0.45 dm3/Nm3 of the cleaned gas the efficiency of dust removal is 85% on average (under the gas consumption of 350,000 m3/h) and reaches 96% (under the gas consumption of 200,000 m3/h). It has been determined that sharp increase in water consumption - above 1.0 dm3/Nm3 of the cleaned gas - causes sharp fall of the dust removal efficiency (up to 40%). This is the result of the formation of a continuous water curtain in the system which prevents the formation of a centrifugal gas movement. The content of gases emitted to the atmosphere (CO, NO, NO2, SO2) obtained at the outlet of scrubbers is significantly lower than the values set by the maximum permissible emission (MPE). СONCLUSION. The use of sub-slurry water as a gas-cleaning solution on the third “wet” stage of gas cleaning organized to extend the already existing at the enterprise system “dust chamber - electrostatic precipitator” will allow to give up the organization of an expensive department of preparation and regeneration of the gas cleaning solution and to carry out the repulping of trapped technological dust in gas cleaning equipment followed by pulp feeding in wet nepheline charge for sintering. The efficiency of scrubber gas cleaning reaches 96% at the designed capacity and at the increased productivity up to 350 thous. m3/h constitutes an average of 85%.