- Quality factors of materials used in furnace construction
Quartz acid furnace lining materials are generally used. The silicon content of quartz sand and quartz powder should be above 99.5%, with oily crystals, transparent and free of impurities. (Silicon content 99.85%, hardness 8, density 2.65, refractoriness 1850 degrees).
- Binder factors used in furnace construction
Traditional furnace building methods generally use boric acid as a binder. Boric acid has both advantages and disadvantages: the advantage is that the bonding is fast at low temperature, and usually starts to bond at 600-700 degrees; the disadvantage is that it is not resistant to high temperature and erosion. Under high-temperature conditions, the lower part of the furnace wall will appear to be hot, so The use of heat is greatly reduced. It is recommended to use boric anhydride instead of boric acid as the binder because boric anhydride has the characteristics of high-temperature bonding, high melting point, high-temperature resistance, and erosion resistance.
- The ratio of materials used in furnace construction
Generally, users make their preparations. During the preparation process, workers do not operate according to the correct ratio. The prepared furnace lining material is uneven and the density is insufficient, resulting in a short furnace lining life, which is generally about 40-50 furnaces. It is recommended to use the finished furnace lining material prepared by a professional manufacturer of furnace lining material. Features: Consistent ratio, uniform mixing, high density, and the service life of the furnace lining is significantly higher than 1-2 times of the artificially adjusted furnace lining material.
- Site factors for modulating furnace lining materials
When users make their preparation, there is no special preparation site, and iron pins, iron beans, and other sundries are easily mixed in the process of preparing the furnace lining, which greatly reduces the number of heats. It is recommended to use the lining material produced by a manufacturer specializing in the production of lining material. Features: With a professional production workshop, there are no iron pins, iron beans, and other sundries.
- raw material factors
At this stage, raw materials are in short supply and prices are rising. To reduce costs, some companies purchase raw materials at low prices, such as iron beans, iron sales, and washing materials, which contain impurities, which greatly erode the furnace lining and significantly shorten the service life.
- the self-factors of medium frequency electric furnace making a charge
Intermediate frequency electric furnace is combined with charge and induction coil. The furnace shell is divided into two parts, with 8 stainless steel screws and several asbestos pads between them. The 8 stainless steel screws cannot be loosened during use, and asbestos pads are indispensable. If the screws are loose, the furnace shell will be twisted back and forth when the molten iron is tapped, and the induction coil will be twisted, causing the furnace lining to loosen and crack, so that the molten iron can seep through the furnace. Solution: Replace the asbestos pad and tighten 8 screws.
- Induction coil factors
The induction coil is made of a copper tube wound into several turns, each with 5-8 copper screws, and an insulated bakelite connection. There is no shortage of screws on the copper ring during use. Once the induction coil is lacking, electromagnetic vibration will be generated, which will continuously hit the furnace lining material, which will loosen the furnace lining material and cause cracks, causing molten iron to seep through the furnace.
- insulating bakelite factors
The insulating bakelite is connected between the coils of the induction coil, and the insulating bakelite supports the weight of the entire induction coil, furnace lining material, and molten iron when the molten iron is out of the furnace. Once it cannot support the weight it bears, the insulating bakelite will bend, and the furnace lining will also become loose at this time. Cracks appear mainly at the joint between the bottom of the furnace wall and the bottom of the furnace, causing molten iron to seep out, and eventually “furnace penetration”. Solution: Use refractory bricks between each insulated bakelite and the furnace shell, so that the furnace shell and the induction coil form a whole, thereby increasing the stability of the induction coil and increasing the number of furnace lining materials used.
- the gap factor between the furnace shell and the induction coil
The intermediate frequency electric furnaces used by general manufacturers are mostly the standard 0.5 ton, 0.75 ton, 1 ton, 1.5 ton, 2 ton, 3 ton… However, to increase the production capacity, some manufacturers increase the induction coil. 0.5 ton becomes 0.75 ton, 0.75 ton becomes 1 ton. The gap between the induction coil and the furnace shell becomes smaller, and the induction coil and the furnace shell form a larger magnetic field source during the smelting process, which consumes both furnace lining materials and electricity. Solution: Replace with a standard intermediate frequency electric furnace (the gap between the induction coil and the furnace shell is generally 250mm-300mm).
- Factors of the wall thickness of intermediate frequency electric furnace
The thickness of the normal furnace wall is 90 mm-120 mm, and the thickness of the furnace bottom is 200 mm-280 mm. However, to expand the production capacity, some manufacturers increase the furnace wall thickness to make the furnace wall thinner. The thickness is reduced to 40 mm-70 mm, and the thickness of the furnace bottom is reduced to 150 mm-200 mm. This is undesirable, and the furnace must be built according to the normal wall thickness to obtain a stable and high yield.
