Boilers used in large heating systems, as a rule, are produced without a screening coating. This is because they are made in accordance with the parameters of the boiler room. The boiler lining serves as a protective coating and is made from materials that provide the necessary characteristics.
Varieties
The main purpose of the protective layer is to reduce the level of heat loss and the risk of burns in workers, and energy costs are also reduced. Particular importance is given to the materials used to create the lining, and the technology of formation. There are several basic schemes, each of which is selected individually and has a high level of efficiency:
- The pipe lining of the boiler consists of lightweight concrete, characterized by thermal insulation characteristics. Using the chromite mass and special plates, the outer layer is made.
- The skeleton scheme incorporates three layers: mineral wool, diatomaceous concrete and chamotobeton.
- Heavy has a limited scope and is suitable only for boiler rooms with a maximum temperature level within 800 degrees. Red brick acts as the outer layer, the inner one is the laying of refractory bricks.
Features
The lining of hot water boilers is a labor-intensive process that requires adherence to technology and proper selection of material. Stuffed compositions are made on corundum, carbundum or chromite basis. Liquid glass often acts as a bonding base. The amount of mass produced depends on the surface to be treated and the required thickness.
The composition deposited on the surface is covered with a special mesh made of refractory material. Sealing coating is carried out with magnesite, asbestos or fireclay powder. It is worth noting that the coating can be performed if the mass is not yet frozen.
What you need to know
Basalt fiber, which is highly resistant to temperature, is used to form heat-insulating boards.
In some cases, it becomes more rational to partially lay the boiler. Reducing thermal energy losses and ensuring the safety of staff is possible due to the processing of construction doors. It is necessary to pay attention to the temperature distribution during cooling.
Boiler lining repair begins with the dismantling of the harness, while it is desirable to maintain the basis of the structure for future use. If there are uneven areas on the screens and pipes, you can apply a layer of heat insulator. The lifetime of the structure can be increased due to aluminum coloring compounds used as a topcoat.
Boilers "DKVR"
Systems of this series are designed to ensure the procurement of heated water and heat supply. They allow you to get saturated steam and are often used in ventilation systems. The design has distinctive features in the form of vertically placed pipes and two drums. Boilers of this brand have many positive aspects:
- wide power range;
- use of any type of energy carrier, including fuel oil and gas;
- automated system operation;
- assembly of the structure can be carried out in the boiler room, while the dismantling of the walls is not required;
- the lining of the boilers "DKVR" is made of any materials suitable for the intended mode of operation;
- the reliability of the aerodynamic and hydraulic systems provides a high level of efficiency.
Boiler lining: technology
An obligatory step before lining is a hydraulic check of the boilers. Further, the lining of the boiler surface and the outer lining are performed. The materials used for lining must have refractory properties, it is also necessary to carefully sift fireclay powder, sand and clay before use. Cement, refractory and red clay should not contain foreign inclusions, lumps and small debris.
Before starting work, it is necessary to prepare a refractory mixture, tools and bricks of the same size. Each row of masonry must be checked with a building level to prevent the formation of depressions and bulges. You can verify the quality of the laying of corners using a steel angle. As it becomes clear, the lining of steam boilers is a rather complicated process that requires compliance with all norms and rules, therefore, work can only be undertaken if there is knowledge and relevant experience. In most cases, it is better to contact specialists, since even a minor flaw can lead to serious consequences in the future.
Features
There should be no cracks or chips on the insulating layer. Before laying refractory fireclay bricks, it is sorted, the material must be of the same size without damage. The use of broken or cracked bricks is strictly prohibited, as this significantly reduces the structural strength. Rough edges also reduce the tightness of the seams.
Solution
Equally important is the mixture used for masonry. It should have a uniform structure without inclusions. For laying fireclay bricks , a solution based on clay and fireclay powder is suitable. The clay's fat content determines the amount of powder. It is worth noting that salt and river sand can not be added to the composition, despite the fact that such ingredients are often found in solutions for laying stoves.
The thickness of the mixture during complex lining should be within 2 mm, with normal masonry, an increase of up to 3 mm is allowed. The result obtained directly depends on observing the proportions of the ingredients and thorough mixing. The consistency should be of medium density. The solution is mixed only in pure water, this ensures the absence of lime and other impurities. It is recommended to prepare the composition in a separate, pre-cleaned container.
Boiler lining: description
Before starting work, all used elements must be cleaned of droplets of solution, corrosion and contamination. The connection points of the fittings are connected with a wire with a diameter of about 2 mm or welded using electric welding. The use of aluminum and copper wire is undesirable.
Bitumen is applied in a uniform layer to the reinforcement and fixing elements needed to strengthen the concrete.
Softwood is used for the manufacture of formwork, with the exception of larch. The sides adjacent to the concrete mortar are carefully processed and curved. It is possible to use paper or clay with high plasticity to seal gaps in the formwork. Double formwork is suitable for lining a vertical surface or at an angle of at least 40 degrees. It is recommended to coat the wooden surface with a lubricant in order to avoid its adhesion to concrete. As a lubricant, you can use a solution consisting of water and mineral oil.
Furnaces and boilers in industry today remain indispensable objects, so often there is a need for repair and modernization of such structures. In addition, the boiler must be lined and, if necessary, the replacement of elements that fail.