DEVICE FOR CONTROLLED HEATING OF SILICON BARS Russian patent published in 2009 - IPC H05B1/02 

FIELD: chemistry; electro-chemistry.

SUBSTANCE: present invention pertains to the chemical industry, and particularly to silicon production in reactors of hydrogen reduction of polychorosilanes, and can be used for controlled heating of polycrystalline silicon bars in a reactor. The outcome is achieved by that, the rectifier unit of the input supply voltage of the device, consisting of two independent rectifiers, has a circuit which provides for serial or parallel connection of the rectifiers. A voltage of 1000 V is obtained from a series connection of the rectifiers, which is used in the initial period of growing silicon bars. Parallel connection of the rectifiers produces 500 V, used in the final stage of growing silicon bars, which uses more than 1000 A. Powerful transistor switches for controlling the heating current are controlled using a pulse-duration conversion method. Rectification of pulsed current of transistor switches is done using a power impedance coil, connected in series with the heated bar and a diode, reverse connected to the supply and closing the circuit of the impedance coil through the heated bar in the off-state period of the transistor switches. Control of the current regulator is done using a microprocessor system with an operator console. Initial heating of the silicon bars to working state is done using the operating voltage of the device through series connection and warming up parts of the silicon bars.

EFFECT: design of a device for controlling heating of silicon bars with high utilisation factor of electrical energy and high smoothing factor of direct current, used for heating the silicon bars.

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