YIRAN natural gas roller hearth heating furnace mainly uses roller table to transport heat treatment material. A roller is installed at a certain distance along the whole length of the furnace. The material runs on the roller, and the burner can be arranged on the top and the bottom of the roller for heating. There are two types of roller, ring roller and flat roller, which can only be used for heating plate. Flat roll can be used not only for heating plate, but also for section steel, pipe and bar. Roller outer sleeve material is usually heat-resistant steel, some also use silicon carbide. High temperature roller hearth furnace uses water-cooled shaft with adiabatic lining of heat-resistant steel furnace roller or water-cooled furnace roller. In order to prevent the furnace roll from bending, the roller working at high temperature must be rotated continuously. Roller hearth furnace is widely used in normalizing, annealing, quenching, tempering and other heat treatment processes because of the material heated on both sides, heating faster and more uniform. The roller hearth reheating furnace heats the thin slab sent from the continuous caster to the rolling temperature evenly according to the technological requirements. The function of roller hearth heating furnace:
The main results are as follows: 1. The roller hearth reheating furnace heats the thin slab from the continuous caster to the rolling temperature evenly according to the technological requirements. The entering temperature of continuous casting slab in the production line is generally between 850C and 1050 ℃, the outgoing temperature (rolling temperature) is between 1100 ℃ and 1150 ℃, and the temperature is raised by 50 ℃ -300C in the furnace domestic demand. The temperature difference between the length and width of the slab should be less than ±10 ℃, and the temperature at the edge of the slab should be 40 ℃ higher than that at the middle of the slab.
2. In the process of rolling, the furnace can store several pieces of the billet. When the rolling mill changes roll or stops rolling, the thin slab sent by the continuous caster can be stored in the heating furnace, which ensures the normal production of the continuous caster, and the furnace plays the role of buffer storage. According to the requirements of rolling process, the buffer time should be ≥ 12 min. to ensure the rolling mill has sufficient time to change roll and deal with accidents.
3. In the production line of thin slab continuous casting and rolling, in addition to the roller hearth furnace, there are also some production processes that make the combination of electric induction heating, coil insulation furnace and shorter roller hearth furnace, step furnace to meet the above requirements. However, due to various factors, this combined heating method has not been greatly developed. At present, the roller hearth heat treatment furnace with longer furnace length is still the mainstream heating equipment in the production process of thin slab continuous casting and rolling.
Features of roller hearth furnace:
1. Furnace roller: cobalt alloy roller ring, high temperature performance, not easy to crack, long life.
2. Anti-deviation function: in the design of furnace roller, the deflection of furnace roller itself is skillfully utilized, which makes the billet automatically align in the course of operation, thus thoroughly solving this problem and effectively reducing the cost of production operation.
3. Installation of furnace roller: the reducer and furnace roller are connected by rubber to simplify the equipment manufacturing process, which reduces the project investment and the running cost in the actual production.
4. Selection of the furnace roll refractory: the furnace roll of the roller hearth furnace is in the running state for a long time, so the insulation of the furnace roll is very important. The YIRAN roller hearth furnace adopts a kind of no-baking castable between light and heavy castable, which effectively solves the insulation of the furnace roller, and the effect is very ideal, and the maintenance cost of the furnace roller is greatly reduced.