In the sintering plant, blast furnace shop, open-hearth furnace shop, slabbing mill, hot strip mill, cold-rolling shop No.1, cold-rolling shop No.3 and also in the foundry shop different gaseous fuel is used in 204 main aggregates (furnaces): blast furnace gas, coke oven gas, natural gas and also their mixtures (blast furnace-natural gas and blast furnace-coke oven gas). Special requirements are imposed on metallurgical and reheating furnaces because together with economy of power resources it is necessary to improve the quality of the final products.
The research laboratory of metallurgical and reheating furnaces of the central laboratory are busy doing research work and searching for ways to increase the efficiency of fuel consumption, development of power saving modes and technologies, control of its fulfillment and also improvement of the rolled stock quality. All these jobs are accomplished together with other research laboratories of the central laboratory, technical department, chief power engineer department, department on automatic control system of the technological process, automation and mechanization department, technical services of the Works’ shops.
In 2007 certain important power saving technical measures, scientific and research works and assignments on new techniques were developed and introduced into production with direct involvement of the laboratories. These measures included introduction of optimal heat engineering modes of the work of metallurgical units of the sintering and open hearth furnace shops, equipped with jet-niche (recess) burners; optimization of thermal and hydraulic heating modes of the slabbing mill soaking pits by setting optimum ratio of air consumption and mixed gas in the conditions of variable combustion heat (calorific value) of gas mixture, and also by means of pressure regulation of combusted products under the soaking pit cover; optimization of the heat mode of operating reheating furnaces of hot strip mill by reducing the calorific value of the mixture by means of using automatic system of regulation of the ratio of consumed blast furnace gas and natural gas.
As a result of introducing these and other jobs the consumption of reference fuel has been reduced by 76379.4 tons. The total economic effect amounted to 32.2 mln UAH. Still the specific fuel rate per 1 ton of products remains very high. In 2007 in the sintering shop it amounted to 4.8 kg of reference fuel (in 2006 it amounted to 5.1 kg); in the blast furnace shop — 116.0 kg of reference fuel (116.2 kg); in the open hearth furnace shop — 62.3 kg of reference fuel (65.7 kg); in slabbing mill — 26.9 kg of reference fuel (26.8 kg); in hot strip mill shop — 10.3 kg of reference fuel (9.3 kg); in cold rolling mill No.1 — 29.2 kg of reference fuel (30.6 kg); in cold rolling mill shop No.3 — 57.5 kg of reference fuel.
To provide fulfillment of the jobs the laboratory does instrumentation measurements of the smoke gases composition on the content of O2, CO2, CO, NO, coefficient of excess air; temperature and pressure of smoke gases and environment; consumption of air, needed for combustion, and also the quantity of smoke gases; temperature of working area, armor of fuel consuming metallurgical and reheating furnaces and surface of metal when charging and removing it from the reheating and heat-treatment furnaces.
For this purpose quite precise optic pyrometers of firm ‘Raytek’ are being used. They are successfully used for heat engineering measurements of temperature in metallurgical and reheating furnaces. To determine the combustion quality of combusted fuel heat engineering measurements with the help of the universal measuring instrument MSI 150 Pro-1 firm “Drager” are done.
Apart from this daily analysis of specific fuel consumption, oxygen in the open-hearth furnace shop, blast furnace shop, sintering plant and analysis of the work of the air heaters of the blast furnaces are done. Daily the temperature and heat modes of more than 100(!) metal heating curves are analyzed in the rolling shops and also the availability of rejections. The results of the analysis of the heating modes are delivered to the open hearth furnace shop, slabbing mill, hot- strip mill and control department. Control of the actual fulfillment of the monthly assignments on production of products, approved by the Chairman of the Board V.A. Satskiy, analysis of production losses, reasons for rejection of finished rolled products (out of order products, claims of the consumers) and unsatisfactory tests of mechanical properties of finished rolled products, and, in particular, observance of thermal and technical modes, are carried out. The above mentioned jobs are fulfilled by 2 groups of laboratories consisting of 9 persons, headed by young specialists Dmitriy Kolomiyts and Jacob Svischenko. The collective of the laboratory consists mainly of young specialists at the age of up to 35 years old: Artyom Nikitin, Alexey Petrik, Sergey Usov, Roman Kinash. These young specialists successfully solve the set assignments, drawing on the experience of highly qualified engineers Irina Gorokhovskaya, Elena Dmitrieva, Vera Litvishkova.
The young specialists of the laboratories continuously upgrade their skill, study technical literature and normative documents. They are coauthors of many inventions on fuel economy, take active part in the work of scientific and technical youth conferences of Zaporizhstal JSC and other metallurgical enterprises in Ukraine and the CIS countries. For each and every worker of the laboratory jobs aimed at the reduction of power carrier consumption and improvement of the rolled stock quality are the main activities of the collective. In 2008 we have to fulfill a certain number of measures of the Works’ power saving programme on improvement of the thermal operation of open-hearth furnaces by adding steam into the ventilated air before its delivery to the open-hearth furnace regenerator checkerwork; development of heat modes for drying and heating of hot-metal ladle cars, lined with main refractory material; optimization of the heat mode of the open-hearth furnace operation by redistributing natural gas to the burners; optimization of the thermal mode of heating the soaking pits by improving the quality of combusted fuel in the working chamber of the soaking pit; optimization of the work of reheating furnaces of hot strip mill shop by increasing the combustion air heating temperature.
ALEXANDER KHOROLETS
Head of research laboratory of metallurgical and heating furnaces of the Central Laboratory