Ma Fulu The joint of furnace lining will affect the service life of furnace lining
The corner connection is more important, they should be staggered, which seems to prevent the appearance of furnace lining. If the connection is not firm, the life of the lining will be affected. The laying method at the corner is staggered, labyrinth, rounded and overlapped.
The labyrinth type is easy to produce gap after shrinkage at high temperature, and the fillet type is difficult to lay. Therefore, there are 1 to 2 fillet type layers, and the rest use the maze type.
As the muffle furnace anchor is located in the middle of the fiber mat, it can be made of ordinary carbon cable structural steel, which can save heat-resistant steel. Compared with the method of laminating and stacking, the method has better resistance to wind erosion. The coating adheres more firmly and the shrinkage trend of the fiber is smaller. However, the field structure of stacking method is not as convenient as that of layering method, and the thermal conductivity is about 20% than that of layered method, so the thickness of furnace lining needs to be increased accordingly. But its use temperature is 50 ℃～ 100 ℃ higher than that of delamination method.
In the heating part and rapid cooling part of the furnace, the temperature difference between furnace and furnace is large, and the thermal deformation of furnace roll is obvious. Therefore, the key of furnace roll, heating part and fast cooling part are selected as research objects. According to the field process regulations, the heating temperature of the heating section is 820 ° C, the tension is 7kn, and the furnace temperature of the fast cooling section is 400 ° C and the tension is 11kn.
A finite element model is established to calculate the thermal deformation of the furnace roll and the buckling deformation of the strip.
In the actual production of muffle furnace, the speed of furnace roll in continuous furnace is more than 200ml. When the rotation time of the furnace roll is long, the temperature difference between the circumferential direction and the radial direction of the furnace roller can be ignored, and the thermal deformation of the furnace roller caused by the uneven temperature distribution of the roller body can be ignored. Be considered. The heat deformation of the furnace roll is calculated using the axisymmetric model shown, and the initial roll shape of the roll is a single tapered roll, and its shape is shown in the figure.
The buckling calculation of strip is carried out by using the shape of furnace roll before and after thermal deformation. Considering the spatial symmetry and periodicity in the furnace, the finite element model shown in the figure is established for buckling analysis. Among them, the strip is a flat strip after cold rolling, with a width of 1600mm and a strip thickness of 0.8mm. The quadrilateral thin shell element is selected as the steel strip unit, and the two cutting edges of the steel strip are displayed in the middle of the upper and lower furnace rolls. In the buckling analysis of the strip steel of muffle furnace, the furnace roll is fixed, the nodes of the longitudinal symmetry line of the tank are restrained laterally, and the tensile stress P is gradually applied to both of them.