RU169143U1 - Plasma torch for spraying metals and refractory compounds - Google Patents

Abstract

The proposed plasma torch belongs to the field of plasma technology and is intended for coating of powder materials. The essence of the utility model is that in a plasma torch for spraying metals and refractory compounds containing a housing, a double-circuit cooling system, a cathode assembly, an anode assembly, an insulator, a cuff, channels for supplying powder material, water and gas lines, there is an additional dosing module, connected by means of transport lines with channels for supplying powder material. The technical result is achieved by increasing the length of the high-temperature portion of the plasma jet without the use of additional nozzles.

Description

The proposed plasma torch belongs to the field of plasma technology and is intended for coating of powder materials.

Known plasma torch for spraying powder materials, containing a housing, cathode and anode nodes, electrical insulating insert, single-circuit cooling system, water and gas lines (Bobrov G.V., Ilyin A.A. Inorganic coating. A study guide for university students. - M .: Intermet Engineering, 2004 .-- 624 s).

The disadvantage of a plasma torch is the low efficiency of the deposition of coatings from refractory materials and a small service life due to the occurrence of intense erosion processes in the anode and cathode assemblies.

The closest in technical essence is a plasma torch for deposition of metals and oxides, containing a housing, cathode and anode nodes, an insulator, a dual-circuit cooling system, water and gas lines (Patent No. 142944, IPC H05H 1/26, publ. 10.07.2014).

The disadvantage of a plasma torch is the lack of efficiency of the spraying process when applying coatings of refractory materials and large particles.

The objective of the utility model is to increase the efficiency of the spraying process when applying functional coatings of refractory powder materials with a wide range of particle sizes.

The problem is solved due to the fact that the plasma torch for spraying metals and refractory compounds, comprising a housing, a dual-circuit cooling system, a cathode assembly, an anode assembly, an insulator, a cuff, channels for supplying powder material, water and gas lines, is equipped with an additional metering device according to the utility model a module connected by means of transport lines with channels for supplying powder material and consisting of an electric motor, a profiled shaft and a consumable washer.

The dosing module serves to change the length of the region of the core of the plasma jet and provides the possibility of efficient penetration to a given depth of particles of both metallic and refractory materials without replacing the plasma torch. The heating, acceleration, and transfer of powder material in the core of a short jet plasma jet allows the particles to not completely melt and prevents them from sticking to the plasma torch body. The transportation of powder material in the core of a plasma jet of a larger length contributes to a significant increase in the heating temperature of larger particles by increasing the time of their movement in the high-temperature region of the jet and ensures the penetration of particles of a refractory material.

The essence of the technological solution is illustrated by the drawings:

in FIG. 1 shows the design of the plasma torch;

in FIG. 2 shows a profiled shaft;

in FIG. 3 shows a metering washer.

The inventive plasma torch consists of four main nodes: cathode, anode, insulator and metering module. It also has a dual-circuit cooling system.

The anode assembly includes a housing 1, a nozzle-anode 2 with an inlet fitting 3 rigidly fixed in the lower part, connected to the first cable-hose.

The cathode assembly includes a cathode holder 4, a cathode 5 with an outlet fitting 6 rigidly fixed at the bottom connecting to a second cable-hose.

The insulator 7 is located between the anode and cathode nodes and has openings for the circulation of coolant (water) from the anode node to the cathode.

The double-circuit cooling system consists of an inlet fitting 3 and an outlet fitting 6, as well as highways, channels and overflow.

Elastic cuffs 8-13 are used as seals in the plasma torch.

There are two channels 14 for supplying powder material.

The metering module includes a profiled shaft 15, inside which is located the channel 16 for supplying transport gas. The left end of the shaft is fixed in the rotor of the electric motor; a removable metering washer 17 is attached to the right profiled end, which is connected via a transport line to a channel for supplying powder material.

A plasma torch for spraying metals and refractory compounds works as follows.

The cathode assembly with a tapered rod cathode 5 cooled internally by running water is located along the axis of the burner. Below is the anode assembly with a conical inlet. The anode assembly is also cooled by water.

The plasma-forming gas is introduced directly into the cavity surrounding the conical tip of the cathode 5. An arc is excited between the conical tip of the cathode 5 and the inlet cone of the anode 2 and is drawn out by the plasma-forming gas.

A profiled shaft 15 with a metering washer 17 fixed to it is driven by an electric motor. The transport gas is supplied through the transport channel inside the shaft 15 and, together with the powder material, passes through the technological holes in the metering washer 17 rotating together with the shaft and enters the transport line, and then enters the anode channel of the plasma torch.

By changing the rotation speed of the metering washer 17, it is possible to increase the length of the high-temperature portion of the plasma jet without the use of additional nozzles.

When a metered dose of powder material and transport gas are supplied to the anode channel, the temperature of the plasma jet changes insignificantly, and the length of the core of the plasma jet increases from (15-20) mm to 45 mm. This fact was experimentally established by high-speed video recording.

The movement of the powder material in a longer core of the plasma jet facilitates the efficient penetration of large particles and particles of refractory material by increasing the residence time in the high temperature region of the plasma jet.

The use of the inventive plasma torch will increase the efficiency of the spraying process when applying functional coatings of refractory powder materials with a wide range of particle sizes by increasing the length of the core of the plasma jet. The use of a metering module will allow for efficient penetration of refractory materials without increasing the power of the plasma arc and without reducing the service life, which will increase the economic efficiency of using the inventive plasma torch.

Claims (1)

A plasma torch for spraying metals and refractory compounds, comprising a housing, a dual-circuit cooling system, a cathode assembly, an anode assembly, an insulator, a cuff, channels for supplying powder material, water and gas lines, characterized in that there is an additional metering module connected by transport highways with channels for supplying powder material and consisting of an electric motor, a profiled shaft and a consumable washer.

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