The working environment and material selection of continuous annealing furnace for strip steel
For the tower furnace heating chamber lining generally with lightweight clay brick 230mm and adiabatic brick 70116mm masonry. That is, high temperature resistance, adiabatic effect and good. In order to ensure its stability, along the height direction should be segmented with metal beams to hold, and in each segment between the expansion interval. The lining of the conservatory is the same as that of the heating room. Slow cooling room cooling method, rely on radiation tube in the non-heating air to fast cooling, some rely only on the brick layer cooling to cooling, some set up a special cooling duct, slow cooling room lining with 12015Omm adiabatic brick.
In recent years, in the tower furnace cooling room widely used spray cooler, eliminating some of the shortcomings of direct water cooling, to achieve a bright plate surface and plate shape neat, fast cooling room length can also be shortened by more than 50%. In order to ensure the tightness, there is a sealing mouth made of refractory fiber between the sealing roller and the entrance and exit, and the steel belt can change the sealing roller under the condition of not polluting the protective gas during operation. The roller of the furnace roller is made of heat-resistant steel.
When carrying out bright heat treatment, due to the use of high H2-containing, low dew point atmosphere, so the furnace is equipped with muffle or high purity alumina brick lining, but also some of the furnace with graphite rollers. Because the alloy elements in stainless steel is very easy to oxidation, in order to achieve a bright surface, the requirements of the heating process in very high purity does not precipitate any harmful gas, but also does not interact with hydrogen. The actual base proves: the use of high purity alumina brick masonry heating section can meet this fee requirements.
High purity alumina brick has high refractoriness and load softening point, good chemical stability at high temperature, does not interact with hydrogen, and does not pollute the protective gas. The brick has heavy (capacity greater than 3g/cm3 and light (capacity 1.35g/cm3) two kinds. The vast majority of the vertical furnace heating chamber uses light bricks, only the bottom few layers and some shaped plate tubes use heavy bricks. The mortar used in masonry is also high purity alumina. Light brick adiabatic parts can be good, brick layer can be thinner, therefore, heat dissipation, heat storage losses are small. But with light brick will increase the furnace blowing dissipation time, so this furnace should try to maintain continuous production. Considering the heat expansion and brick wall stability, along the furnace wall height segment (every 2m or so) with a metal beam to hold up, leaving a certain gap between each segment, filled with adiabatic material.