A medium frequency induction melting furnace consists of two important components: a medium frequency power supply and a heating coil. The medium frequency power supply first rectifies the three-phase AC power (using thyristors) into single-phase DC power, and then the inverter bridge converts it into a pulsed AC current of 500-10000Hz. This strong alternating current is then transmitted to the heating coil (usually made of copper tubing) through a water-cooled cable. This generates a strong magnetic flux with rapidly changing polarity within the melting coil. When the metal or other object to be heated is placed inside the coil, the magnetic flux penetrates the entire object. A corresponding large eddy current is generated inside the heated object, flowing in the opposite direction to the heating current. Due to the resistance within the heated object, a large amount of Joule heat is generated, causing the object's temperature to rise rapidly. This achieves the purpose of heating and melting all metal materials.
A medium frequency induction melting furnace consists of a medium frequency power supply, capacitor bank, water-cooled cables, connecting copper bars, induction coil, movable furnace body, fixed support, magnetic yoke, furnace leakage alarm, water temperature alarm, furnace lining materials, hydraulic system, tilting furnace control panel, hydraulic cylinder, and circulating cooling water.
High power factor: The medium frequency power supply is a voltage-type series resonant inverter power supply. The rectifier always operates at zero degrees, without adjusting the rectification, only adjusting the inversion, resulting in a high power factor greater than 0.95, with no high-order harmonics. This provides substantial benefits to users in terms of energy saving, operation, and production in all melting plants. We guarantee that the equipment's power factor remains above 0.95 under any operating conditions.
Energy saving: Due to the use of a series resonant circuit design, the reactive current is small, significantly reducing power consumption. A 0.5-ton 300KW medium frequency furnace consumes 680 kWh to melt iron at 1450°C and 720 kWh to melt steel at 1600°C. A parallel-connected thyristor 0.5-ton medium-frequency furnace requires a 500KW transformer, while a series-connected inverter 0.5-ton medium-frequency furnace only requires a 300KW transformer to operate normally, and consumes very little power. Long-term calculations show that the savings in capacity usage costs amount to more than 100,000 yuan per year.
The medium-frequency induction melting furnace maintains constant power output throughout the melting process. Compared with parallel-connected inverter medium-frequency power supplies, the power adjustment method is different. Parallel medium-frequency power supplies adjust the DC voltage, while this product produced by our company adjusts the frequency. It is not affected by the amount of furnace charge and maintains constant power throughout the entire melting process. Its superiority is especially evident when melting non-magnetic materials such as stainless steel, copper, industrial silicon, and aluminum. It offers faster melting speed, less burning loss of furnace charge elements, better energy saving effect, and reduced casting costs.
The medium-frequency induction melting furnace requires a smaller power transformer capacity. Taking a half-ton furnace as an example, the half-ton series-connected medium-frequency furnace produced by Luoyang Wanle Electric Equipment Factory only requires a 300KW transformer with a low-voltage side voltage of 380V. This means that for general casting enterprises, a transformer of 315KW or less is sufficient, and the same transformer can be used for lighting, cranes, water pumps, and other power uses.
The medium-frequency induction melting furnace has less burning loss of alloy elements; due to electromagnetic stirring, the metal melt composition is uniform, without segregation; induction furnace melting is easy to control, operating conditions are good, environmental pollution is low, and noise is low; it allows for convenient and economical reuse of metal furnace materials (from small iron filings to large materials that can fit in the furnace chamber). Therefore, medium-frequency induction melting furnaces are widely used for melting cast iron.
The medium-frequency induction melting furnace adopts a frequency-sweeping zero-voltage soft-start method, allowing it to be started or stopped at any time under any condition without impacting the power supply; it offers rapid melting and low production costs; it produces minimal pollution and meets environmental protection requirements; it can be started directly from a cold furnace, and the molten metal can be completely emptied, making it convenient to change the type of melting material.
The medium-frequency induction melting furnace offers flexible and convenient power adjustment, allowing for continuous and smooth regulation; the temperature is uniform and easy to control, resulting in less oxidation loss and uniform metal composition; the power supply system has a fault diagnosis function, making maintenance easy.
The medium-frequency induction melting furnace shell uses a cast aluminum alloy or steel shell structure, occupying a small footprint; the furnace body is easy to tilt and pour, and electric, manual, or hydraulic tilting methods can be selected as needed.
The medium-frequency induction melting furnace is designed with an automatic inverter angle adjustment circuit, which can automatically adjust the load impedance matching to achieve constant power output, eliminating the need to adjust the compensation capacitance and ensuring the equipment always operates in optimal working condition.
