Refractory Lining

Refractory lining is basically a protective layer installed inside the furnace to protect the steel structure from high temperatures. Refractory bricks or monolithic refractories can be used for refractory lining. This selection is determined by the indented heat levels of the furnace and/or the chemical structure of the material being processed inside. Refractory lining is one of the most important things to look for during the installation. A professionally placed lining will increase the lifetime of the furnace and lower the energy costs. In general, refractory lining thickness is in between 80 mm and 300 mm. However, the thickness should be determined for each project differently.

The Shape of the Refractory Lining

Most refractory lining systems are constructed of fire bricks. Monolithic castable refractories are also used for this job, but the fire bricks are the cheaper and easier solution. The brick shape of the refractory lining varies according to the intended use of the furnace. For example, the most commonly used shape is the arch roof. Domes and cylinder geometries are similarly preferred too. Refractory lining is exposed to high temperatures for a long time. This results in complicated stress environments within the lining structure. For this reason, a periodic structural investigation is needed for all types of refractory linings to prevent high repair costs and to ensure continuous production.

Refractory Lining Control Software

During the investigation, the first thing to look for is the thermal response of the lining system. This phase consists of temperature distribution, heat loss, and heat transfer checks. The second part is about thermal expansion, displacement and thermal stress within the lining system. Computerized structural analytical methods are used during the process. Most popular method is called “finite element method” (FEM) and there are many FEM software available. The FEM check can also be done manually. This method treats the entire surface of the refractory lining as a geometric pattern and analyzes each section independently.