1. Classification of industrial furnaces. There are many types of industrial furnaces and a wide range of applications. Industrial furnaces have different uses in different industries. From a professional point of view, we can classify industrial furnaces in different ways.
1.1 Classification according to the presence or absence of heat sources
In the traditional concept, industrial furnaces are limited to thermal equipment that can provide heat sources. In fact, in industrial production activities, many thermal equipment themselves do not have the basic conditions to provide heat sources, such as steel ladles in the steel industry, some reaction towers in the chemical industry, etc., because they have been called furnaces in the long-term habitual appellation. Equipment classification is accustomed to the management of industrial furnaces, and its construction process also has the structural characteristics of general industrial furnaces. Therefore, this type of equipment is also classified as an industrial furnace. Within the scope of the industrial furnace we are talking about today, it can be classified according to whether there is a heat source:
(1) Industrial furnace with heat source: The heat source referred to here includes the heat source provided by various kinds of energy. Such as: solid fuel, liquid fuel, gas fuel, power source and chemical heat. This kind of industrial furnace includes all industrial furnaces that can provide various heat sources for materials. Such as: heating furnace, electric furnace, etc.;
(2) No heat source industrial furnace: The no heat source here means that the industrial furnace does not provide various heat sources for materials. Such as: iron mixer, steel ladle, tundish, chemical reaction tower, etc.
1.2 Classification according to the source of heat
In industrial furnaces, the commonly used heat sources mainly come from gas fuels, liquid fuels, solid fuels, electricity, etc. These heat sources generally have two types in the formation process: one is in the form of flame and the other is in the form of non-flame.
(1) Flame furnace: An industrial furnace that uses the heat released by the combustion of fuel as the heat source. This kind of industrial furnace has simple structure, diverse fuels, diverse structural forms, and relatively low production cost, which can meet various industrial purposes and is widely used in the industry. Such as: all kinds of heating furnaces, etc.;
(2) Electric furnace: An industrial furnace that converts electric energy into heat energy as a heat source. This kind of industrial furnace has high temperature control accuracy, high quality products, and no combustion pollution, but the production cost is relatively high, which makes its application subject to certain Restrictions, mostly used in the production and processing of some high-quality and special materials, such as: steelmaking electric furnaces, electrolytic cells, infrared baking furnaces, etc.;
(3) Other industrial furnaces: In addition to flame furnaces and electric furnaces, there are some industrial furnaces that provide other forms of energy to achieve industrial purposes, such as oxygen top-blown converters for steelmaking.
1.3 Classification according to the process
In the process of industrial furnace, there are generally two kinds of changes in materials: one is that the state of matter changes; the other is that the state of matter does not change. Usually, we call the industrial furnace that changes the state of matter as the smelting furnace, and the industrial furnace that does not change the state of matter is called the heating furnace.
(1) Smelting furnace: In this kind of industrial furnace, the physical state of the material has changed. In order to achieve industrial purposes, some industrial furnaces change the physical and chemical properties of the material while changing the physical state of the material. These industrial furnaces include: blast furnaces and reverberatory furnaces for extracting metal from ore, converters for removing impurities in materials, etc., and iron furnaces for melting metals, etc.,
(2) Heating furnace: This refers to the heating furnace in a broad sense. The common feature is that the heated material in the industrial furnace only changes its physical, chemical and mechanical properties during the entire process, but does not change its physical state. According to the purpose, heating furnaces can be divided into general heating furnaces, heat treatment heating furnaces, roasting heating furnaces and dry baking heating furnaces.
(3) There are also some special types of furnaces such as boilers for producing steam, reforming furnaces and cracking furnaces for chemical production, distillation towers, etc.
1.4 Classification according to the process system
In the production process of industrial furnaces, there are mainly two different technological systems: continuous production system and periodic (or intermittent) production system. Usually we call the continuous industrial furnace as the main process parameter in the industrial furnace does not change with time during the production process. Such as: blast furnaces, coke ovens, rotary kilns, continuous heating furnaces, etc., the process parameters change periodically over time are called periodic (or intermittent) industries. ·Such as: converter, soaking furnace, inverted flame, glass melting furnace, etc.
1.5 Classification according to the heat exchange method
In addition to the above classification, in daily work, according to the different forms of heat exchange in the production process of industrial furnaces, there are also classifications according to different heat exchange methods. Such as: radiant heating, convection heating and layered heating, the radiant heating furnace can be divided into uniform system type, direct directional type and indirect directional type.