Heat treatment and firing under the influence of elevated temperatures with pressure are quite common technological steps in industry. In production in this way, the strength and hardness of the material is achieved, which improves the operational characteristics of the future product. However, the implementation of such operations requires special equipment. This is an extensive segment in which industrial furnaces in various modifications occupy not the last place. They allow you to process the material under high loads, while maintaining the original characteristics of its own design. Another important feature of such equipment is the ability to work with large volumes of materials. However, there are many options for furnaces, each of which has its own capabilities and functions.
What are shaft type furnaces for?
This is a type of industrial furnace, which is designed for firing, hardening and heating. As raw materials can be used and raw materials, and lump rocks, as well as bulk materials. In particular, such aggregates work effectively with carbonate rocks and ore materials. As for metals, the shaft-type heat treatment furnace is suitable for the maintenance of cast iron, aluminum and copper alloys.
For the effective use of the capacities of such equipment, it is necessary to carefully calculate the volumes of the material being laid. For example, the size fraction of the bulk material may be in the range of 60-120 mm. However, there are also industrial furnaces capable of receiving material with a diameter of more than 240 mm. This ability depends on the capacity of the camera and the performance of the unit. Even if physically the equipment can accept an object with large dimensions, this does not mean that the camera will properly process it by thermal exposure. Therefore, initially the power characteristics of furnaces are compared with the qualities of the target material.
Shaft furnace
The basis of almost any shaft furnace consists of four parts - loading and unloading units, as well as a chimney with a heat treatment chamber. Skip, cube and conveyor mechanisms are used to load raw materials. The choice of this or that design depends on two main parameters: firstly, on the characteristics of the supplied material, and secondly, on the operating conditions of the unit. For example, a skip system provides for the use of a bucket with a reverse stroke and a winch, so it can be considered as a universal loading mechanism. The unloading device, which is supplied with the shaft furnace, also has several parts, but the main component is an intermediate tank, sealing and metering material.
To exhaust the exhaust gas, a chimney is used in the form of pipes, which are most often located in the rear of the furnace. In modern models, this system often has a complex structure with filters and an automatic control system. As for the combustion chamber, which is supplied with the shaft furnace, the main process of processing the incoming raw materials takes place in it. Using the control panel, the user adjusts the parameters of its operation in accordance with the requirements of the material manufacturing technology.
Principle of operation
The function of such furnaces is based on the principle of counterflow, in which the falling layers of raw materials are washed by oncoming gas flows. The processed material successively passes through several technological sections, including the drying zone, heating, firing and cooling chambers. In some models, the firing chamber coincides with the area in which the fuel burns. Hot gases form here. Of no small importance in the efficiency of the process is the structure in which the unit is made. If the shaft furnace is designed to work with large volumes of heterogeneous raw materials, then the distribution system comes to the fore in the choice of design. Most often, this function is performed by cone-dividers, due to which the automatic process of filling the furnace is carried out.
Varieties of aggregates
There are several classifications that categorize this type of furnace. In particular, laboratory and industrial units can be distinguished by the nature of the thermal effect. If the former are more likely to achieve high processing results, then for the latter the intensity of the overall process and the capacity of the loading chamber are more important. Also, designs differ in the type of material used. If we talk about lumpy material, then equipment for the production of bricks is the most common in this segment. In different areas, units that work with fuel resources, ore and rocks, gas, etc. are in demand.
Mechanized and electric furnaces
Most models of this type used in the manufacturing sector are powered by electricity. Their structure includes a fan that circulates the air masses, helping to increase the heating intensity. By the way, one of the main advantages of electrical units is the ability to regulate power. This option is especially useful when working with low density raw materials. For example, an electric lime kiln allows you to maintain basic quality properties, quickly changing the parameters of the temperature effect at different stages of processing. Mechanized units operate on a hydraulic drive system. The raising and lowering of the lid in such equipment is carried out through compact mini-stations, which are filled with oil.
Benefits of shaft furnaces
The operational advantages of such furnaces are determined by structural features. Nevertheless, there are common advantages, which led to the widespread distribution of such units. In particular, mine equipment for brick production allows for short periods of time to provide heat treatment of large volumes of clay raw materials. The possibilities of working with metals, gas, bulk materials and even waste allow us to talk about the versatility of such furnaces.
Conclusion
The process of technological modernization is most noticeable in industries and construction. The departure of old systems and mechanisms is especially pronounced, replaced by more functional and reliable analogues. However, the shaft furnace confirms that traditional equipment may well compete with automatic and electronic developments. Of course, the introduction of individual automation elements is inevitable, but the general principle of operation of such furnaces remains the same. The most popular models of this type are represented precisely by hybrid plants, which have absorbed the best features of the classic design and advanced technological innovations.