High-temperature processing of materials is one of the key operations in many industries, where the thermal effect is included in the list of the main technological processes. The conditions for organizing this procedure may be different, which causes differences in the characteristics of the equipment used. In general, the segment of units, due to which intensive heat treatment is carried out, is formed by high-temperature furnaces for industrial use.
Classification of equipment according to the principle of heat generation
Today, there is no universal way to generate thermal energy that would be equally suitable for different operating conditions. However, it is possible to single out a narrow group of the following types of the most popular furnaces used for high-temperatureheating:
- Fuel. The traditional method of generating heat, which is generated from chemical energy by burning solid, gaseous and liquid fuels.
- Electrical. A wide segment of units that are convenient and safe to use. In the category of high-temperature electric furnaces, more modern induction and electric arc models also stand out. A common disadvantage of such equipment is the high cost of electrical energy, which is spent in large volumes.
- Autogenous. Furnaces of this type work due to the reactions of combustion and oxidation of the elements contained in the workpieces being processed. For example, in the course of blowing liquid iron with oxygen, carbon is oxidized with natural heat release. It is obvious that the use of autogenous furnaces is economically beneficial, since practically no additional fuel cells are required, but not all production facilities normally provide for technological processes with oxidation and combustion. As a rule, this applies to the areas of metallurgical processing of metals and alloys.
Chamber Furnaces
This is one of the most common high temperature unit designs, designed to provide a thermal effect with rapid heating to the desired level. In order to maintain the uniform distribution of thermal energy in production, special gas and oxidizing media are additionally used. The maximum heating mode athigh-temperature chamber furnaces reaches 1800 °C, if we are talking about standard industrial models for metallurgical production. Electricity usually acts as an energy source - the power potential varies from 0.5 to 3.5 kW on average.
Tubular furnaces
A variety of high-temperature models of furnace equipment with the possibility of directional supply of heat flows. The design provides for heating and separate blocks, the rotary mechanics of which allows you to work at different angles, depending on current requirements. Some models of tubular high-temperature furnaces are equipped with a quartz reactor with gas-tight heads. This design solution provides the effect of double combustion of gases, which also creates conditions for minimizing the initial fuel resources. As heat emitters, sectional-type heating-insulating modules are usually used, providing heating up to 1200 °C.
Features of muffle furnaces
For efficient operation in aggressive environments, which often occurs in the industrial processing of raw materials, various types of muffle furnaces are used. They can be used with direct impact on the structure of gases, dust, steam, water and other waste products. Insulation tasks are solved by special heat-resistant materials. For high-temperature furnaces operating in the temperature range from 1150 °C to 1300 °C, in particular, ceramic elements are used that do notonly protect the firebox from negative external influences, but also contribute to an even distribution of heat from the outside. The design may also include special bearing pipes, through which heat is radiated purposefully along certain contours and for short periods of time.
Melting furnaces
As a rule, these are units with a small heating chamber designed to service compact workpieces. The target materials for processing in such furnaces include non-ferrous metals that require special conditions of thermal exposure. There are also special lines of models for performing operations in the laboratory, provided with a casting trough with the possibility of accurate dosing of the melt. The average heating values in this type of high-temperature furnaces range from 1000 °C to 1500 °C with the possibility of fine regulation. Some modifications of the firing units also belong to this variety.
Key features of stoves
Even within the same type of high-temperature industrial furnace, operating parameters can vary widely. The average indicators, with which large manufacturing enterprises most often work, can be represented as follows:
- Unit power - from 0.2 to 5-7 kW.
- Temperature range - from 300 to 2400 °C and more.
- The volume of the working chamber of high-temperature furnaces is from 2.5 to 20 dm3.
- Design weight - from 2 to 100 kg.
- Voltage - commonly usedthree-phase networks for 380 V.
Workflow organization
Installation of equipment is carried out in a stationary way, sometimes requiring a preliminary foundation in the form of a heat-resistant cement screed. The necessary communications and technological equipment for supplying blanks are brought to the furnace. Some engineering software components are included in the basic package. For example, the cooling system is often implemented using a fan. High-temperature water-cooled ovens are equipped with a circulation pump of suitable capacity, which is integrated into the local water supply infrastructure. Management today in almost all industrial heating units is provided by programmers with sensors and controllers of operating parameters. Thermostats can be integrated into the central control systems of the enterprise, which allows you to comprehensively monitor the performance of equipment in the overall context of the production process, taking into account the characteristics of parallel technological operations.
Conclusion
The main scope of this equipment is metallurgy, as well as certain branches of the chemical and food industries. But even within the framework of such industries, the processes of thermal action are heterogeneous. As processing technologies become more complex, the approach to organizing thermal treatment operations also changes. Also, the requirements for structuralexecution of high-temperature furnaces. Materials for such equipment today are represented not only by tool steels, but also by heat-resistant ceramics, which makes the structures easier and more practical to maintain. Approaches to the management of furnaces are also changing. The introduction of the same automation with programmable modules increases the efficiency of workflow control, and at the same time increases the operational life of equipment and reduces energy costs due to balanced control.
