A steam boiler is one of the oldest devices for converting thermal energy into mechanical work, in which the working fluid is water vapor. The design of steam boilers has not changed for hundreds of years. By definition, a steam boiler is understood to mean a device designed to produce high potential water vapor. A large number of various models of various designs are used on the market, used both in everyday life and in industry. In this article we will get acquainted with the principle of operation, operating rules and the scope of application of steam boilers.
The basic principle of operation of various types of steam boilers is unchanged and simple - in a boiler in a closed volume, water is heated with its transformation into water vapor, which is subsequently used to perform useful work. The source of energy for heating can be the energy of the sun, earth, or more traditional gas, solid fuel or electricity.
Depending on the purpose of the boilers, the steam produced is divided into two types: saturated and superheated. Saturated steam is characterized by a temperature of the order of 100 ° C and pressure within one atmosphere. It is generated by domestic boilers and is mainly used in heating systems of private houses.
Superheated steam is a high-potential energy source with a temperature of up to 500 ° C, can be under pressure up to 260 atmospheres. The scope of application of superheated steam: industrial plants and power engineering - turbine rotation in thermal and nuclear power plants. Installations producing superheated steam are characterized by higher efficiency.
The arrangement of steam boilers of various types is identical and differs only in minor details.At the first stage, there is an obligatory stage of water purification from metal salts and excess oxygen. This is necessary to prevent the formation of scale and corrosion of boiler elements. Rust and scale significantly reduce the effectiveness of the device, and in some cases can completely render it unusable.
The purified water is supplied to a special tank, from which it passes through a pipeline to the collector in the lower part of the boiler, where the heating zone is located. Here, the water is heated to 100 ° C and the formation of water vapor, which independently rises through the pipes.
The resulting steam contains a large amount of moisture and is unsuitable for use, so the next step is to drain the working fluid. Dried steam enters the steam line for its intended use.
In industrial boilers to produce superheated steam, at the last stage in the steam line, saturated steam is additionally heated to increase its temperature and pressure to specified limits.
According to the principle described above, all steam boilers work, the difference in the device is only in the size of the boiler, the type and location of the collector, the presence of safety devices, the complexity of automation, as well as the type of fuel used for operation.
Steam boiler - a device operating under pressure and related to hazardous installations. If used improperly, a thermal burn with superheated steam is possible, and in exceptional cases an explosion of the entire installation.
When operating such boilers, it is important to strictly observe the device operation rules prescribed by the manufacturer and regulatory documents.
IMPORTANT! Installation and periodic maintenance should only be carried out by qualified specialists.
The main reasons for the failure of steam boilers, according to statistics, are:
- low-quality water treatment, leading to increased corrosion of boiler elements and significantly reducing its efficiency;
- lack of periodic reading of the fuel combustion chamber;
- incorrect setting of boiler automation.
The presence of safety devices and automation control, subject to professional installation and configuration, makes modern steam boilers safe devices.
Steam boilers in terms of application are divided into two large classes of domestic and industrial.
Home appliances generate saturated water vapor, which is used as a coolant for heating systems. Typically, such systems run on solid or liquid fuels.
Industrial boilers use superheated steam under high pressure, which can significantly increase the efficiency of the devices. Coal, fuel oil, gas or atomic decay energy is used as fuel for industrial plants.
Industrial steam boilers are used in the electric power industry, production, construction, etc. These devices can be called the basis of the industry. Here are just a few examples of industrial applications:
- steaming of concrete structures;
- sterilization and disinfection in the food industry;
- power generation;
- driving actuators of machines and mechanisms.