RU2471885C1 - Device to produce silicon-carbide fibers - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: proposed device consists of one or more chambers. Every chamber is composed of glass tube with two unions for feeding gas mix of alkyl chlorosilanes with hydrogen, to mercury unions, and two drain unions to remove fluid products formed in making aforesaid fibers therefrom. Every said chamber accommodated taper-shape glass elements with holes at vertices converging along core displacement and soldered in between gas feed mercury unions to make vessel for mercury. Core is composed of tungsten wire or carbon fiber while abrasive-proof perforated inserts are fitted in said converging part of said tapered glass elements.

EFFECT: higher reliability and efficiency, ease of servicing.

1 dwg

Description

The present invention relates to devices for producing monofilament silicon carbide fibers obtained by pyrolysis of alkyl chlorosilane vapors on a heated electrically conductive core (tungsten wire or carbon fiber).

Known methods and devices for producing silicon carbide fibers (Zirlin A.M. Continuous inorganic fibers for composite materials, M .: Metallurgy, 1992, p.178).

In the process of producing silicon carbide fibers, glass tubular chambers are used, interconnected by gates. The gates are used to seal the chambers and supply electric power to the core using mercury. Mercury is retained by capillary forces created by small-diameter holes through which core and fiber pass.

The closest in technical essence to the proposed device and adopted by us as a prototype is a device for producing boron threads (Pat. RF 2066696, IPC C21D 9/54, C23C 14/00, 1996). The device includes a prefabricated housing in the form of tubular reaction chambers, contact shutters with side openings, gas and mercury fittings, a contact shutter made in the form of a hollow cylindrical insert placed in a tubular reaction chamber, consisting of three parts of a sleeve with internal thread and external grooves the ends for plugs adjacent to the grooves with an external thread and with external and internal guide cones with holes in the vertices, dies installed in the plugs and pressed to the tops of the cones by bursting elements, o-rings of elastic material located in the grooves and having a width greater than the width of the groove.

This device has significant disadvantages, which include:

- Numerous prefabricated and fasteners;

- reducing the tightness of the device;

- difficulty in cleaning up mercury;

- the use of large quantities of mercury;

- high voltage;

- high labor costs when assembling and disassembling the device;

- availability of special tools;

- environmental pollution.

The objective of the invention is to simplify the device, increase its reliability and performance, reduce the amount of mercury used, facilitate maintenance, and improve the ecological environment.

This problem is solved by the fact that the proposed device for producing silicon carbide fibers, consisting of one or more chambers, made in the form of a glass tube with two fittings, for supplying a gas mixture of alkylchlorosilanes with hydrogen, two mercury fittings and two drain fittings with the possibility of removal from one or more chambers of liquid products formed upon receipt of silicon carbide fibers, while truncated cone-shaped glass elements with holes in the vertices are narrowed inside each chamber moving along the direction of core movement for deposition of silicon carbide and soldered between the gas supply fittings to form a mercury reservoir, the core being made in the form of a tungsten wire or carbon fiber, and inserts of abrasion-resistant material with holes are located in the tapering part of the truncated conical glass elements.

The use of hemispherical thin sections allows a quick, tight and reliable connection of glass non-separable chambers and allows alignment of the production line, in contrast to the known rigid joints, such as threads or tapered thin sections.

Figure 1 schematically shows a device for producing silicon carbide fibers.

The device is a glass non-separable cylindrical chamber - 1, having two gas fittings for supplying gaseous reagents located perpendicular to the chamber axis - 2, two mercury fittings - 3 and two drain fittings for removing high-boiling liquid products - 4, the fittings are made in the form of glass tubes and have a threaded connection at the ends, truncated conical glass elements - 5, tapering in the direction of core movement, are placed inside the chamber, mounted in a narrow part of the truncated conical elements Inserts made of abrasive material with holes of small diameter, and for connecting several chambers at the ends are connecting sections in the form of a hemisphere - 6.

The device operates as follows.

Through one or more glass non-separable cylindrical chambers 1, interconnected using connecting hemispherical sections 6, center the processing line, then the core (tungsten wire) is pulled along the axis and heated by direct transmission of electric current, which is fed to the lower mercury fitting 3. In parallel core through the nozzle 2 pass a gas mixture of alkylchlorosilanes with hydrogen. Passing through the cone-shaped elements 5, having a narrowing in the direction of core movement and a chamber filled with mercury, silicon carbide is deposited on the heated core surface. To carry out the core drawing through the chamber filled with mercury and to hold mercury in the tanks on the tops of the conical elements, inserts with a small diameter hole of abrasion-resistant material are soldered. In the process of producing silicon carbide fibers in the chambers, high-boiling liquid products are formed, which are removed through the drain fittings 4.

Claims (1)

A device for producing silicon carbide fibers, consisting of one or more chambers, characterized in that each chamber is made in the form of a glass tube with two fittings for supplying a gas mixture of alkylchlorosilanes with hydrogen, two mercury fittings and two drain fittings with the possibility of removal from one or more chambers liquid products formed upon receipt of silicon carbide fibers, while truncated cone-shaped glass elements with holes in the vertices narrowing in the direction are located inside each chamber the core for the deposition of silicon carbide and soldered between the gas supply fittings with the formation of a mercury reservoir, the core is made in the form of a tungsten wire or carbon fiber, and inserts of abrasion-resistant material with holes are located in the tapering part of the truncated conical glass elements.