The difference between inner hole plasma spray gun and conventional plasma spray gun

       The biggest difference between the inner hole plasma spray gun and the conventional plasma spray gun is the structure of its nozzle. Usually, the plasma beam emitted by the inner-bore plasma torch is at an angle of 90 degrees to the axis of the torch. In addition, according to the special working environment of inner hole spraying, the inner hole plasma spray gun should have the characteristics of small size, short spraying distance, good cooling of the gun body, and can work in a higher temperature environment.

    Large inner hole spray gun (PQ-1N) features:

    Inner hole spray gun (PQ-1N), in view of the shortcomings of the nylon powder feeding tube connected to the nozzle of the 3MBT spray gun, which is easy to burn out during spraying and the gas distribution ring is easy to ablate during operation, the metal powder feeding tube and the gas distribution ring are used instead. The material was changed to polyimide. The maximum power of the gun is 40kW, and the maximum size of the outer profile is 90mm. It is suitable for spraying inner holes with a diameter of φ102mm or more. The spray gun, like the general cylindrical gun, still uses straight-hole nozzles for spraying, and there are four types of nozzles. The spray gun can work with argon or nitrogen, and a gas distribution ring should be added when spraying with argon. The powder feeding method of the spray gun adopts the powder feeding outside the gun.

    The characteristics of the inner hole spray gun (PQ-2N):

    The medium-bore spray gun (PQ-2N) was successfully developed on the basis of 7MT. The advantage of the 7MT spray gun is that the nozzle and electrode have a long service life, but it has the fatal weakness of poor melting ability, and can only spray some materials with lower melting points. or very fine powder. In response to this situation, a nitrogen nozzle was designed and the powder feeding method was improved, the melting capacity was significantly improved, the refractory materials alumina and zirconia could be sprayed, and the deposition efficiency was also improved. Since the spray gun is used to spray the middle inner hole, the straight hole nozzle cannot be used like the large inner hole gun, but the inclined hole nozzle is used instead. The bevel angle of the nozzle is 65 degrees (for argon spray) and 75 degrees (for nitrogen gas spraying) spraying). The maximum power of the spray gun is 38.5KW, and the minimum hole diameter that can be sprayed is φ 60mm.

    Small Bore Spray Gun (PQ-3N) Features:

    Small bore gun (PQ-3N) is developed on the basis of 7MST gun. The structure of the spray gun is basically the same as that of the middle inner hole spray gun. The 7MST spray gun can only be sprayed with argon gas, the maximum power is 35kW, and it also has the disadvantage of poor melting ability. It can only spray materials with low melting points such as copper, nickel and cobalt, and cannot spray aluminum oxide and zirconia. In response to this situation, new nitrogen nozzles and argon nozzles were designed, the powder feeding method was changed, and the cooling of the nozzles was strengthened, so that the maximum power of the small inner hole spray gun reached 40kW, the melting capacity was significantly improved, and fine-grained oxides could be sprayed. Aluminum powder and zirconia powder, the deposition efficiency is also greatly improved, and the minimum pore size that can be sprayed is φ45mm