The high temperature function of intermediate frequency electric furnace lining mainly depends on the physical and chemical function and mineral composition of the refractory materials used. Under the premise of the selection of raw and auxiliary materials, the sintering process is the key process to make the lining obtain superior microstructure and fully develop its high temperature resistance function. The densification level of lining sintering is related to the chemical composition, particle size ratio, sintering process and sintering temperature of refractory. Furnace building technology
　　1, the furnace to use:
　　a, mica paper, heat insulation, insulation performance is good, save electricity, in use to press the real mica paper, to avoid gaps. - Dongguan City Nancheng Runyuan medium frequency electric furnace factory
　　b, asbestos cloth, heat insulation, insulation performance is slightly poor, not recommended.
　　2, the refractories used in building the furnace should be selected according to the melted metal, whether it is bought with refractories, or it is matched by itself, the following disposal should be carried out:
　　a, hand selection: the primary removal of lumps and other impurities;
　　b, magnetic separation: it is necessary to remove magnetic impurities;
　　c.
　　5, dry ramming materials: must be slow drying treatment, drying temperature of 200℃-300℃, heat preservation for more than 2 hours, and then heating. - Dongguan City Nancheng Runyuan medium frequency electric furnace factory
　　6, the selection of binder: quartz sand with boron anhydride (B2O3) instead of boric acid (H3BO3) as a binder, the participation of 1.1%-1.5%, other refractory materials choose different binders.
　　7. Selection and ratio of quartz sand as furnace material:
　　8, the selection of quartz sand: It should be noted that not all SiO2≥99% of the quartz sand can be used as induction furnace lining data, the main is the size of the quartz grain, the larger the grain, the less lattice defects, the better (such as crystal quartz sand SiO2 high purity, white surface, clear.) The larger the furnace capacity, the higher the grain requirements.
　　9, ratio: the ratio of quartz sand for furnace lining: 6-8 mesh 10%-15%, 10-20 mesh 25%-30%, 20-40 mesh 25%-30%, 270-mesh 25%-30%.
　　10, lining knot: lining knot quality tightness is directly related to the quality of sintering. The sand particle size distribution does not segreate on average during knotting, the sand layer after knotting has high density, and the probability of cracking after sintering is reduced, which is conducive to improving the service life of induction furnace lining. - Dongguan City Nancheng Runyuan medium frequency electric furnace factory
　　11, tying the bottom of the furnace: the thickness of the furnace is about 280mm, and it is filled with sand four times to avoid uneven density when manually tying, and the furnace lining is not dense after baking and sintering. Therefore, it is necessary to strictly control the feeding thickness, the ordinary sand filling thickness is not more than 100mm/ time, the furnace wall is controlled within 60mm, and many people are in shift operation: now there is also a furnace building machinery, which is slow to twist and shift around the furnace, and the force is average to avoid the formation of uneven density. - Dongguan City Nancheng Runyuan medium frequency electric furnace factory
　　12, knotting furnace wall: furnace size is different, furnace lining thickness is also different for 50-100mm, batch to participate in dry knotting material, the average cloth, the thickness of the filler is not more than 60 mm, knotting 15 minutes (manual knotting), until it is flush with the upper edge of the induction ring. The crucible die is not pulled out after knotting, and induction heating effect occurs during drying and sintering.
　　13, baking and sintering standards: In order to obtain the three-layer structure of the furnace lining, the baking and sintering process is roughly divided into three stages: - Dongguan Nancheng Runyuan medium frequency electric furnace factory
　　14, baking stage: slowly heating up at a low power (speed of about 2 hours), heating the crucible mold to 300 ° C, holding heat for 1h, the goal is to thoroughly sweep the water in the furnace lining.
　　15, semi-sintering stage: appropriately increase the power heating to 900℃ (about 30 minutes), hold for 1h, add iron and then heat up to 1200℃, it is necessary to control the heating rate to avoid cracks.
　　16, sintering stage: when sintering at high temperature, the sintering structure of the crucible is the foundation of improving its service life. The sintering temperature is not enough, the thickness of the sintering layer is insufficient, and the service life is definitely reduced.
　　Dongguan city Runyuan intermediate frequency furnace factory Main products: stainless steel melting intermediate frequency furnace, molten copper intermediate frequency furnace, intermediate frequency furnace harmonic filter, forging diathermy intermediate frequency furnace, molten iron intermediate frequency furnace, molten steel intermediate frequency furnace, molten aluminum intermediate frequency furnace. Welcome business calls to negotiate cooperation.