Investigation of Pobeda furnace bubbling zone physics using cold modeling method Part 3. The hydro-gas dynamics of combined blowing of liquid by gas using bottom and lateral lances

Abstract

Hydro-gas regularities of liquid combined blowing by gas were studied using cold modeling method at Archimedes criterion for lateral Arl = 12÷120 and bottom blowing Arb = 5÷60 simulating Pobeda bubbling unit. The blowing was performed simultaneously by bottom lance vertically fixed in centre of reactor and by the lateral lance which was attached at an angle 5° to the horizontal axis. The quantitative estimation of instantaneous and average circulation velocities (Vav) of liquid flow elements in different bath areas, depending on the location of blowing zone and Archimedes criterion, was performed. The liquid motion trajectory was determined. A vortex zone was revealed near the liquid surface and the reactor shell, where instantaneous velocity of the liquid flow elements changes from 69.9 to 181.1 mm/s and Vav = 123.8 mm/s. The circulation flows fade in the bulk of liquid and Vav decreases from 123.8 to 47.0 and 54.1 mm/s. It was shown that, in general, circulation velocity depends on the blowing intensity and appears to be higher for the zone of overlapping of lateral and bottom streams. The dynamic blowing conditions, which ensure the direct contact of lateral and bottom jets leading to their interflow and increased spatter formation, were identified. The characteristics of 3 types of surface oscillations for interface phases “pure liquid- gas-liquid layer”, as well as the estimation of the lateral and bottom blowing impact on the type of oscillation were provided. It has been noted that the introduction of the bottom blowing (Arb = 5) causes the wave-like motion of liquid (the 2nd type) along with the transverse oscillations of the 1st type, and at higher values of Arb = 25 the angular oscillations of the 3rd type develop. It has been shown that the presence of a lateral jet at the combined blowing decreases angles of bath swinging to 8–12° to horizontal axis. For the estimation of oscillation intensity, Δhl = (hl )max – (hl )min value, which means the difference between maximum (hl )max and minimum (hl )min height of liquid for the full-wave oscillations (τ), was introduced. The height of liquid (hl ) was plotted as a function of τ, Arl , Arb, Δhl was determined on the basis of obtained graph values, which varied upon modeling over the range of 7.7–69.5 mm. The relation between the liquid circulation velocity and the oscillation value (Δhl ) was established for different bath zones and dynamic conditions of the blowing. The impact of all oscillations types on potential erosive lining wear of Pobeda bubbling unit and the completeness of adoption of charging material nearby the bath surface was investigated.