Used vertical stainless steel mixing tank with total volume 450 l. Internal diameter 820 mm x length of straight side of wall 795 mm. Top open, has bolted stainless steel cover. Bottom elipsoidal, with central discharge outlet. Tank is equipped with bottom mounted nozzle for feeding gase into the liquid. Tank has top mounted propeller agitator, driven directly by el motor 0,37 kW, 1370 rpm, 230/400 V, 50 hz. There is also top mounted, welded to the wall, perforated stainless steel coil with connection.