Selection of checker brick material and brick type for glass kiln regenerator

Selection of checker brick material and brick type for glass kiln regenerator

The grid body is an important part of heat storage and heat transfer in the regenerator. The grid bricks are required to be able to withstand high temperature, corrosion resistance, large heat storage, fast heat transfer, and resistance to rapid cooling and rapid heating.

Measuring the heat storage effect of the regenerator is usually determined by the heating area of the grid, that is, the surface area of the grid that can conduct heat exchange. The larger the heat storage area, the more heat will be accumulated and the more heat will be released, which can fully increase the preheating temperature of air and gas, which is more beneficial to the combustion of fuel.

Different alkaline checker bricks are used according to the different temperatures at the top, upper, middle and bottom of the regenerator and the amount of flying material. The top (above 1400°C) has high temperature and a lot of flying material, so it is easy to form a liquid phase with the brick body. , it is easy to stick flying materials and cause stress in the brick body. Therefore, zirconium bricks with excellent creep resistance at high temperatures or 98% high-purity magnesia bricks are used on the top (due to the MgO in the high-purity magnesia bricks and the particles flying into the regenerator. The ultrafine powder SiO2 reacts to form a low-temperature eutectic. Therefore, the 1#3# top grids that are easy to enter the flying material are mostly made of zirconium bricks, and the end regenerator grids that are not affected by the flying material are mostly made of 98 % high purity magnesia brick).

The upper part (1000-1400°C) has less flying material settling, so high-purity magnesia bricks can be used.

There are very few flying materials in the middle part (800~1000°C), but it is the sulfate agglomeration area, which easily causes the magnesia bricks to react with the flying materials to form magnesium silicate (MaSi03). At the same time, during the reaction process of Glauber's salt in the batch and the fuel combustion process The formed S02 and S03 are also easy to react with magnesium oxide:

MgO+S02-MgS03 Mg0+S03-MgS04

The generated magnesium sulfate or magnesium sulfite repeatedly solidifies and liquefies, and the volume expands, causing structural damage to the magnesia bricks. Therefore, direct bonded magnesia bricks (DMC-12) with good thermal stability and low porosity are selected for this part (in areas with high environmental protection requirements) The use of magnesia-chromium bricks is not allowed in the area, and periclase + forsterite bricks are often used).

The temperature at the bottom (below 800°C) alternates between hot and cold, the load is heavy, and it is less eroded by alkaline materials. Therefore, materials with good thermal stability and load-bearing strength are required. Low-pore clay bricks (DN-12, DN-13 or DN-15) or sillimanite bricks. If the performance of various alkaline bricks is not considered and used in general, it will affect other lattice bodies when one part of the lattice body is damaged, thereby reducing the life of the overall lattice body. Because most alkaline refractory bricks, including magnesia chrome bricks, are easily damaged in an atmosphere containing cracked hydrocarbons (reducing atmosphere). Therefore, alkaline bricks can only be used in air regenerators and cannot be used in gas regenerators.