STUDY OF THE PHYSICAL CHARACTERISTICS OF STREAMS EMERGING FROM COHERENT-TYPE NOZZLES

The main controlling factor in oxygen converting with top blowing is the stream of oxygen, which penetrate the metal bath and promotes the flow of heat, mass exchange and chemical processes. The inherent characteristics of the oxygen jet are created by the nozzle tip with nozzles that may differ in design depending on the issue they solve. 
            In the electrometallurgical industry, coherent nozzles consisting of a central nozzle for supplying the main oxygen jet and a surrounding annular nozzle for supplying shielding gas, mainly methane, are used to ensure deep penetration of the oxygen jet into the melt and to improve the mixing processes of the bath. This design of the nozzle, according to available published data, ensures the elongation of the main jet while preserving its momentum. 
The paper presents the results of a study using a modified liquid manometer of the features of the action of jets flowing out of nozzles of a coherent type of different designs (the ratio of the outer and central parts of 25%, 50% and 75%) under blowing conditions that correspond to the conditions of top blowing during industrial oxygen conversion. The conducted research made it possible to establish that when the share of the peripheral part is more than 50%, the main controlling link of the jet is the central nozzle, and when the share is smaller, it is the peripheral slotted part. The jets flowing out of the nozzles of the coherent type with the share of the peripheral part more than 50% have a greater force of action on the liquid compared to the force of action of the corresponding central nozzle, by the amount from 33 to 74%relatively. The design of nozzles with a share of the peripheral part of the order of 25% practically does not create conditions for improving the power characteristics of the jet. 
According to the results of the established conclusions, it is possible to recommend the use of nozzles of the coherent type with a share of the peripheral part of more than 50% as nozzles, for example, of the second row for top blowing lance, which have a slag-forming effect, contributing to better penetration into the melt compared to the corresponding cylindrical ones, that will intensify the processes of mixing and slag formation in the bath