The introduction of coke ovens into operation began in the 50s of the last century. The net volume of the first typical furnaces was 21.6 nm³. Further in the article we will consider the device of the named equipment.
General information
If we consider the device of this furnace as an aggregate used in industry, then it consists of several parts:
- The main part is the chamber, in which the process of coal coking takes place directly.
- Next are the heating piers, where the gas needed to heat the stove burns.
- Another of the main parts is the regenerator, which serves as a utilizer for the heat of the exhaust gases generated after the combustion of products.
In addition, coke ovens can be assembled into batteries, and batteries, in turn, can be packaged in blocks.
In the Russian Federation, batteries consisting of 61, 65 or 77 furnaces are most often operated. If you look at foreign industry, then there batteries can include up to 120 ovens.
Side feed furnaces
In coke ovens with side supply, the gas and air supply for heating the unit is adjusted along the heating wall. The adjustment process is carried out by replacing the regulatory bricks-registers, as well as burners. Their location is at the base of the heating channels, which are characterized by constantly elevated temperatures, as well as the inevitable clogging occurring in these channels.
Such conditions greatly complicate the process of adjusting the supply of gas and air, and also do not allow the installation of control devices with the necessary accuracy.
However, these shortcomings were eliminated in coke ovens with a bottom feed. With this design, the means that regulate these processes are carried outside the masonry, which makes them easily accessible to personnel involved in the maintenance of the furnace. Changing control devices in furnaces with this design is much easier.
Furnace design
In order to begin the process of manufacturing coke, it is necessary to load the mixture into the furnace. To implement this procedure, the unit has a hole that is located in the upper ceiling of the chamber. There is also an opening for the removal of volatile gases generated during coking. The latter, passing through the gas outlet, fall into a special chamber for collecting gases, from which they are sent to the recovery department.
At both ends, the chamber is equipped with doors that are removed at the end of the coking process. Through the resulting holes, the finished coke is pushed out of the furnace using a coke ejector.
It is also worth noting that coke ovens are a completely sealed design. This is necessary in order to exclude the possibility of suction of atmospheric air into the furnace, which will also have to be heated if this happens. And this, in turn, will increase the cost of heating gases, which will negatively affect the final cost of the product.
Coke Production Technology
The production process of this material is carried out in several stages:
- The whole process begins with loading the charge into the furnace chamber and then leveling the material using a bar. In order to avoid smoke from the atmosphere when opening the chamber at the time of loading the material inside the furnace, a vacuum is created by injecting steam or gas. In addition, a special gas suction system from the chamber can be used.
- Next, the process of coking of the charge. During this time, the material lends itself to all the necessary influences that lead to its conversion to coke, as well as to PCG. Also at this stage, the furnace productivity is distinguished, which is determined by the time necessary to obtain finished coke from the moment the charge is loaded inside it.
- Unloading of finished products, that is, coke or, as it is also called, coke "pie" is carried out in a quencher. For this operation, an automatic coke ejector is used.
Batteries
The coke oven battery is a specialized metallurgical unit whose main purpose is the procurement of coke - fuel for blast-furnace production of pig iron.
It is important to note that such batteries are used for a rather long period of time without stopping. Most often, their work period is at least 25 years. During all this time, a high temperature is maintained inside the furnace, and the masonry of the structure itself is abraded by products when they are discharged from the chamber.
For these reasons, the construction of coke oven batteries is carried out only from refractory materials. These materials must withstand:
- mechanical forces applied by the machine during operation;
- burst pressure during coking;
- withstand the pressure of all structural elements lying on these refractory materials.
It is also important to note that metallurgical equipment such as batteries include 45 to 69 coke ovens.
Classification
Like any other industrial equipment, The named furnaces, which are part of metallurgical plants, have a number of parameters, according to which they are classified. These include:
- The location of the chambers in the furnace, which can be either horizontal or vertical.
- The method of loading the mixture into the furnace, as well as the subsequent procedure for issuing the finished product. There are two types of furnaces - with top loading and subsequent lower delivery of material, as well as with upper loading and subsequent delivery through side openings.
- Two coke production processes are also distinguished, which can be continuous or batch.
- One of the parameters for classification is the method of heating a particular furnace. This procedure can be carried out both using blast furnace, mixed or coke oven gases at the same time, and using only coke oven or only blast furnace gases.
In the territory of the Russian Federation, most often, PC-2K furnace systems with side supply are put into operation at metallurgical plants.
Hydraulic operation
The hydraulic mode of operation of coke ovens is a clear distribution of pressures in the heating system of the entire unit as a whole. Special studies, as well as the long period of operation of such a mode of operation, revealed parameters that characterize the correct mode of operation of the furnace:
- The gas pressure in the coking chamber throughout the entire period of operation should be higher than in other compartments.
- The gas pressure in the chamber where the coking process takes place is a variable.
- The gas pressure in the heating system in the upstream must be lower than in other places.
Furnace operation
The most important parameter in the operation of the furnace is its performance. Almost all other aggregate indicators affect this parameter. The period of coke production, that is, productivity, most depends on such characteristics as chamber width, wall thickness, temperature in the walls, properties of refractory materials, and also the quality of the charge.
It is worth noting that currently the maximum speed that can be achieved from coke oven - 32 mm / h. It must be understood that this parameter is derived taking into account the maximum allowable temperature that can be developed and maintained in the chamber. Also, one of the most important parameters that must be observed for the operation of a coke oven is the temperature of the finished pie. It should be from 1,000 ° C to 1,050 ° C.