Power knowledge about induction furnace

Author : Hongteng Time: 2022-04-19

Today, the editor of Hongteng will summarize the knowledge about the power supply of furnace installation.

Power supply equipment includes high-voltage or low-voltage switchgear, intermediate frequency power supply (intermediate frequency generator set or thyristor inverter), power transfer switch, compensation capacitor and intermediate frequency control cabinet (power distribution console in front of the furnace), etc. The electrical part of large intermediate frequency furnace is also Including crucible leakage furnace alarm system.

The intermediate frequency power supply is composed of two parts: the intermediate frequency power supply cabinet and the capacitor compensation frame. With the improvement of facility power, the power supply voltage of intermediate frequency power supply is also different: at present, the common ones are 380V, 575V, 660V, 750V, 950V, 1100V; the number of power supply phases is divided into three-phase, six-phase and twelve-phase.

The composition of the intermediate frequency power supply cabinet: the main switch, the rectifier thyristor, the inverter thyristor, the main control board, and the smoothing reactor.

The main control board is equivalent to the human brain. At present, the constant power main control board is widely used. There are two processes of wave soldering and manual soldering. The wave soldering process is stable and the failure rate is low.

The thyristor is the core of the intermediate frequency power supply, and its accurate use is critical to the operation of the facility.

The working current of the thyristor ranges from several hundred amperes to several thousand amperes. Under normal water cooling conditions, the current overload capacity can reach more than 110. Considering the surge voltage, manufacturers often select silicon components according to 3-4 times the working voltage when manufacturing facilities.

Of course, good main control board protection and good water cooling conditions are necessary. If the circulating water is too hard, scale will form inside the water cavity, resulting in poor heat dissipation; if the water cavity enters leaves and other sundries, it will also cause poor water flow.

The exact installation pressure of the thyristor is 150-200KG/cm2. When the facility leaves the factory, it is generally press-fitted with a hydraulic press. Manual use of an ordinary wrench cannot reach this value with a large amount of force, so there is no need to worry that the silicon will be crushed when pressing manually.

It is normal for a facility to damage three or five thyristors per year. If silicon is often burned, the electric furnace will be shut down and production will be affected, which will cause alertness.

The above is what we share with you about the power supply knowledge of induction furnaces. Welcome to pay attention to our Luoyang Hongteng to give more furnace service for you.

Video of the use process of the melting furnace

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