FLUID TYPE SEALING METHOD IN THE HEARTH ROLL SUPPORTING BLOCK OF HIGH TEMPERATURE ANNEALING FURNACE

摘要

The present invention prevents external air from entering into the support block of the hearth roll mounted in the jet cooling zone where low pressure is formed in the high temperature annealing furnace for annealing the electrical steel sheet at a high temperature, thereby preventing surface defects and explosion of the strip and safe work. The present invention relates to a method for sealing the inside of the hearth roll support block of a high temperature annealing furnace, which enables to seal the inside of the hearth support supporting block mounted in the jet cooling part of a high temperature annealing furnace which performs simultaneous decarburization and annealing of electrical steel sheets. In a method; When the pressure in the annealing furnace is 0.1 ~ 0.7mmW.C, the oil supply pressure is 0.8 ~ 1.1mmW.C, and the specific gravity of oil is the weight ratio between 15 ℃ oil and 4 ℃ same volume of pure water (15 ℃ / 4 ℃) is 0.60 ~ 0.90, the tie point is maintained at 4 ~ 6 Cst at 100 ℃ conditions, the mixed gas is added in weight percent ammonia: 10-30%, nitrogen 70-90%, input pressure is 1.1 The temperature of the oil is maintained at 0 to 15 ° C., and the sealing is performed at ˜1.3 mmW.C.;According to the present invention, the iron loss value and magnetic flux density of the product due to external air intrusion generated in the jet cooling part of the high temperature annealing furnace are prevented in advance, thereby completely blocking the oil inflow through securing the steel sheet quality and securing the sealing force. It is possible to produce high quality electrical steel sheet, and can also provide the effect of securing the safety of the annealing furnace.