Strategy of automation of electric arc heating of steel melt in ladle-furnaceStrategy of automation of electric arc heating of steel melt in ladle-furnaceStrategy of automation of electric arc heating of steel melt in ladle-furnace

Prices hike for consumable materials and energy carriers, increase of requirements to steel quality stipulate the items of intensification of ladle treatment processes and decrease of their energy- and material capacity. Analysis of energy losses in ladlefurnace accomplished, as well as basic factors effecting the energy costs during treatment analyzed. A methodology elaborated for making thermal balance of ladle-furnace: it was proposed to present the melt treatment process in ladle-furnace as a series of separate operations, each having specific features of the process (heating, desulphurization, alloying) and their combination. Based on analysis of 20 thousand heats passports at ladle-furnace of MMK BOF shop, a mathematical model of energy supply system of ladle-furnace was elaborated. Based on the analysis made, a strategy of heating automation was proposed. In particular, electric losses were emphasized, t. e. total losses of electric arc energy, in which provisionally losses at arc open part radiation were included. Control of those flows creates conditions for heating efficiency increase. Conclusions were made that decrease of electric losses is observed at prolonged (about 8−12 min) heating periods and sufficient amount of slag, as well as at injection of additives after heating. Such a mode provides decrease of thermal losses by 4−5%. A new technology of steel melt treatment in ladle-furnace was proposed, characterized by decreased consumption of electric energy.

Thermal characteristics of an arc column in the stabilization zone of an air-operated laminar plasma torch

The method of universal characteristics of an electric arc is described as a mathematical basis for the heat exchange model of an electric arc in the processes of electric arc heating in electrical engineering. Application of this method for calculation of the temperature characteristics of an arc column compressed by the walls of the discharge channel in the stabilization zone of a laminar plasma torch operating in air is considered. An example of the temperature profile calculation of a wall-stabilized arc for a plasma generator with a discharge channel diameter of 5 mm operating in air at an arc current of 60 A is presented. Calculated results are compared with the results of experimental studies of this plasma generator.

Effect of Taper Angle of the Optical Fiber Microprobe in Power Collection

The objective of this experiment is to study the effect of taper angle of the optical fiber microprobe in power collection. Optical fiber microprobes with taper angle from 10° to 23° were fabricated using the automatic fusion splicer by applying one-sided pulling and electric arc heating technique. It was found that the maximum power detected by a small taper angle probe was only -34.22dBm. The highest optical power collected by the optical fiber microprobe in this study was -25.01dBm with taper angle of 22.9°. Large taper angle probe receives more light at the tip which increases the sensitivity of the probe.