The structure of the plasma spray gun

       The spray gun is a plasma arc generator designed to produce a high-enthalpy, high-velocity plasma jet and to deliver spray powder smoothly into the jet. The optimal selection of spraying process parameters and the stability of the spraying process depend to a large extent on the performance of the spray gun. The spray gun collects water, electricity, gas, and powder. In the case of high power and light weight, the structure is more complicated. The key to the spray gun lies in the design of the nozzle, the electrode and the water and gas paths.



    The overall structure of the spray gun is divided into front and rear insulation structures and inner and outer insulation structures from the position of the insulator between the positive and negative electrodes. The front and rear insulating structure is composed of three parts: the front gun body, the rear gun body and the intermediate insulator. The front gun body fixes the nozzle, and the rear gun body fixes the electrode. The high-power spray gun shown in Figure 2-50 is of this structure. The inner and outer insulating structure is composed of three parts: the gun body, the middle insulating sleeve and the electrode rod. The front end of the gun body is fixed with the nozzle, and the front end of the electrode rod is fixed with the electrode. The high-power spray gun shown in Figure 2-51 is of this structure.

    For the adjustment of the front and rear position of the electrode, the structure of the spray gun can be designed to be adjustable or fixed. In the powder feeding position, it can be designed as powder feeding inside the gun or powder feeding outside the gun.

    No matter what kind of structure is used, the concentricity of the nozzle and the electrode, the dielectric strength and the airtightness to water and gas are very important for the performance of the spray gun in design and manufacture.