Cold air driven spray painter

Abstract

The spray painter consists of ultrasonic nozzle, heater, powder feeder and other parts. The ultrasonic nozzle is mounted in the inlet of the spraying chamber, and the controller connected to the air compressor with air tank is connected via a powder feeding switch and pressure regulating switch to the heater and the powder feeder. The heater has one end connected to the ultrasonic nozzle. There is one powder recovering unit in the outlet of the spraying chamber. The ultrasonic nozzle is connected with the powder feeder and consists of three parts of contracting section, throat and expanding section. The present invention has high powder feeding efficiency, long service life and no oxidation.

Description

technical field [0001] The invention relates to surface spraying treatment of materials, in particular to a cold air power spraying device. Background technique [0002] In the existing technology, two kinds of technologies are mostly used for the surface spraying treatment of materials. One is the traditional thermal spraying technology, such as: flame spraying, arc spraying, plasma spraying, supersonic flame spraying and explosive spraying, etc. The common characteristics are Use different heat sources to heat various materials to be sprayed, such as metals, alloys, ceramics, plastics and various composite materials, to a molten or molten state, and form a "particle mist flow" with the aid of high-speed atomization of airflow to deposit on the pretreated work. The surface forms a coating that is closely combined with the substrate in a piled up shape. Since thermal spraying requires a very high temperature during the spraying process, when the flame stream leaves the nozz...

AI Technical Summary

Problems solved by technology

Because thermal spraying requires a very high temperature during the spraying process, when the flame stream leaves the nozzle, it will be exposed to a large amount of air, which will seriously oxidize the sprayed material, thus limiting the scope of thermal spraying.

In order to solve the above oxidation problem, the further improvement of thermal spraying technology is to use low-pressure plasma spraying and vacuum plasma spraying, but the size of the sprayed workpiece is limited in the vacuum chamber, and the coating can only be prepared for powder materials with a stable liquid phase, and Spraying equipment is expensive

The second is cold spraying technology. Cold spraying was invented by Russian scientists in the late 1980s. Patents of Russia, the United States and the European Community (among them: 1) Russian patents, the patent numbers are 1674585 (1991), 1603581 (1993), 1618778 (1993), 1773072 (1993), 2010619 (1994); 2) European patent, the patent number is 0484533 A1 (1992); 3) U.S. patent, the patent number is 5302414 (1994)) discloses a kind of air-cooled power spraying device, The powder feeder is integrated with the supersonic nozzle. As shown in Figure 1, the drum is driven by a motor, and the powder is pushed into the gas-powder mixing chamber through the drum. There is a compressed gas inlet at the lower end of the powder feeder, and through two Two outlets respectively introduce the gas into the lower end of the powder feeder drum and the upper part of the powder to balance the pressure of the powder feeding chamber. The disadvantage is that the gas pressure at the upper end of the powder may be lower than that at the lower end, causing the powder to flow back

In addition, the diffusion section of the nozzle structure is conical, which is convenient for processing, but the pressure loss is large, it is difficult to achieve the best injection speed, and the service life is low (1000 hours)

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