DonNTU   Masters' portal

Abstract

Introduction

We live in an era of industrial development, construction, distribution of various means of telecommunications, transportation, etc. People need a lot of products that produce Metallurgic industry. Steel industry should be update.

Continuous furnace (CF) – is a complex technical installation, which is designed to heat the metal. Continuous furnace is a furnace of continuous operation [1].

Methodical furnaces are divided into: pusher counterflow (methodological) furnace pusher straight-counterflow furnaces, walking beam furnaces, roller hearth furnace. They have positive and negative aspects [2, 5]. The main purpose – heating the metal to the required parameters and reducing the cost of the product.

1 Theme urgency

In our time, rises production in the metallurgical industry. The final material must be of high quality. Enterprises must compete in domestic and foreign markets. The design of units deprecated and needs reconstruction with modern components. Requires complex automation of metallurgical industry. In this work continuous furnace № 1 JSC Donetskstal is the subject of automation.

2 Goal and tasks of the research

The aim of the work – to investigate the transient heating of blanks in the continuous furnace, to identify the heating mode with a minimum consumption of the gas mixture and to develop a system of automatic control for continuous furnace. We need to use microprocessor technology and develop a scheme to manage this unit.

The process of heating the metal is shown in Figure 1. Metal passes successively through a methodical, welding and soaking zone against the movement of the flue gases, and then when he have the desired temperature at the surface and the thickness of blank enters the roller mill. Flue gases are moving in the direction of boot windows, pass through a ceramic and a metal recuperate and released into the air through the chimney [6, 8–10].

Діаграма станів автомата Мура

Figure 1 – The heating of the metal in the continuous furnace
(animation: 9 frames, 7 cycles of repeating, 113 kilobytes)
(1 – soaking zone, 2 – welding zone, 3 – methodical zone, 4 – ceramic and metallic recuperators)

3 Requirements to the automation system

There are several of parameters and requirements that must be considered when designing the automation system. The following are the main ones [7, 11–13].

The parameters that need to be automated in continuous furnace:

  • the parameters that need to be automated in continuous furnace:
  • thermal management;
  • temperature changes on the surface of the workpiece;
  • change in temperature over the thickness of workpiece;
  • control flow of the gas mixture;
  • speed control of the passage of the material;
  • pressure control in the workspace, etc.

    The heating of the metal is as follows:

    1. Temperature surface of the blanks at the exit of the furnace is the deviation of ± (10–15) K.
    2. The blanks must be heated sufficiently. The temperature difference over the thickness of blanks not more than (20–40) K.
    3. The temperature drop along the length should be minimal.
    4. The speed of heating the metal to (500–700) ° C is not less than the setting value [2, 14].

    Requirements for the automation system:

  • ease of operation of automatic control system;
  • the possibility of changes in temperature;
  • reducing the error in the regulation;
  • reducing the cost of repairing and service of equipment;
  • availability of economic effect, reducing fuel consumption.

    The tasks that must be met for automation:

    1. Getting information about the temperature of the metal with a given accuracy [4, 15, 16];
    2. Model of the unit should be simple;
    3. Additional factors (inadequate design of MP, insufficient heat capacity);
    4. The heating of the metal with different geometrical and weight parameters.

    Results of the work:

  • account of the advantages and disadvantages of different types of heating continuous furnace, selection of optimal type for the object of automation;
  • modeling of transient heating of blanks in the furnace methodical;
  • development of the block diagram of an automation system;
  • development of the structural scheme of the device automated heating control.

    Conclusion

    Investigated the process of heating the metal in the continuous furnace. Modeled the transient heating of blanks, determined the most economical mode of heating with a minimum flow of the gas mixture. It is established that the heating flue gases against the motion to reduce the time spent in the blanks continuous furnace, but when heated with direct smoke movement – decreases the temperature difference across the thickness of the workpiece.

    For continuous furnace developed a block diagram of an automation system of heating the metal and heating scheme control device of the metal.

    In further developments need to implement a model of heating of the metal by means of numerical methods.

    This master's work is not completed yet. Final completion: December 2012. The full text of the work and materials on the topic can be obtained from the author or his head after this date.

    References

    1. Глинков Г.М. АСУ ТП в черной металлургии / Г.М. Глинков, В.А.Маяковский: Учебник для вузов. – 2-е изд., перераб. и доп. – М.: Металлургия – 1999. – 310 с. // Режим доступа: http://bookinist.net...
    2. Ревун М.П. Высокотемпературные теплотехнические процессы и установки в металлургии: [учебн. пос.] / М.П. Ревун, Б.Б. Потапов, В.М. Ольшанский, А.В. Бородулин. – Запорожье: ЗГИА. – 2002. – 443 с. // Режим доступа: http://www.cgntb.dp.ua...
    3. Кривандин В.А. Металлургическая теплотехника. В 2-х томах. Т.2. Конструкция и работа печей / В.А. Кривандин, И.Н. Неведомская, В.В. Кобахидзе и др. – М.: Металлургия, 1986. – 592 с. // Режим доступа: http://www.cgntb.dp.ua...
    4. Кривандин В.А. Тепловая работа и конструкции печей черной металлургии. / В.А. Кривандин, A.B. Егоров – М.: Металлургия, 1989. – 462 с. // Режим доступа: http://www.cgntb.dp.ua...
    5. Кривандин В.А. Металлургическая теплотехника т.1 / В.А. Кривандин, В.А. Арутюнов, Б.С. Мастрюков и др. – М.: Металлургия, 1986. – 424 с. // Режим доступа: http://www.cgntb.dp.ua...
    6. Грум-Гржимайло В.Е. Пламенные печи. / В.Е. Грум-Гржимайло – М.: Госмашметиздат, 1932. // Режим доступа: http://books.google.com.ua...
    7. Глинков Г.Я. Теоретические основы автоматического управления металлургическими процессами / Г.Я. Глинков, М. Д. Климовицкий Уч. пос. для вузов по спец. Автоматизация метал. произв-ва и Теплотехника и автоматизация метал. печей – М: Металлургия, 1985. – 304 c. // Режим доступа: http://www.cgntb.dp.ua...
    8. Тайц Н.Ю. Технологии нагрева стали. / Н.Ю. Тайц – М.: Мегаллургиздат, 1962. // Режим доступа: http://lethnope.web44.net...
    9. Тайн Н.Ю. Методические нагревательные печи. / Н.Ю. Тайн , Ю.И. Розенгарт – М.: Металлургиздат, 1964. – 408 с. // Режим доступа: http://www.twirpx.com...
    10. Буглак Л.И. Автоматизация методических печей / Л.И. Буглак, И.Б. Вольфман, С.Ю. Ефроймович и др. – М., Металлургия, 1981. – 196 с. // Режим доступа: http://www.cgntb.dp.ua...
    11. Глинков М.А. Основы общей теории печей / М.А. Глинков – М.: Металлургиздат, 1962. – 575 с. // Режим доступа: http://www.cgntb.dp.ua...
    12. Кравцов А.Ф. Расчет автоматических систем контроля и регулирования металлургических процессов / А.Ф. Кравцов, Е.В. Зайцева, Ю.Н. Чуйко – К.: Вища школа. – 1981. – 320 с. // Режим доступа: http://www.cgntb.dp.ua
    13. Казанцев Е.И. Промышленные печи. Справочное руководство для расчетов и проектирования / Е.И. Казанцев – М.: Металлургия, 1975. // Режим доступа: http://books.google.com.ua
    14. Климовицкий М.Д. Приборы автоматического контроля в металлургии. Справочник. / М.Д. Климовицкий, В.И. Шишкинский – М.: Металлургия, 1979. – 296 c. // Режим доступа: http://books.google.com.ua...
    15. Климовицкий М.Д. Оптимизация работы нагревательных печей. / М.Д. Климовицкий – М: Металлургия, 1965. – 163 c. // Режим доступа: http://www.cgntb.dp.ua...
    16. Бутковский А.Г. Методы управление системами с распределенными параметрами. / А.Г. Бутковский – М.: Наука, 1975. – 568 с. // Режим доступа: http://www.cgntb.dp.ua...