The function of the nozzle system

The most important part of the nozzle system is the abrasive water nozzle of the water nozzle assembly. In order to meet the requirements of fine cutting, the nozzle should have excellent jet characteristics and a long service life. The water nozzle is the performance component of the high-pressure water jet generating equipment, and the effect of the water nozzle It is through the shortening of the cross-section of the inner hole of the nozzle that the pressure energy of the high-pressure water is collected and converted into kinetic energy, and finally the material is cut and processed by spraying out in the form of a high-pressure water jet. High-pressure water jet nozzles can be divided into conical nozzles according to the cross-sectional shape of the nozzles. Conical nozzles with cylindrical outlet section are introduced. Conical nozzles with cylindrical outlet section are introduced. Disc nozzle

The nozzle is usually made of sapphire, and the shape is simple and simple to process. The cone-shaped nozzle with cylindrical outlet section can improve its flow coefficient, and is now the most commonly used continuous water jet nozzle. The quality of the nozzle has a certain influence on the quality and power of the water jet. Therefore, the water jet nozzle should meet the following requirements:

1) Ensure that the jet has the proper function;

2) The density of the jet should be good to ensure that the jet has a long range;

3) Long service life;

4) It is convenient to disassemble and protect;

5) Low cost.

Nozzles used for abrasive water jets, because under the effect of high-pressure water and abrasives, the materials requested to select nozzles should have certain mechanical strength, wear resistance, corrosion resistance and technicality. Because the nozzle is a vulnerable part, the cost should also be considered, usually tungsten carbide cemented carbide, synthetic diamond and other materials are used.

Tungsten carbide cemented carbide has high hardness (93hrc), high compressive strength (6000mpa) and excellent wear resistance. Tungsten carbide cemented carbide abrasive water jet nozzles can be formed with hydrostatic pressure restriction or steel mold limit. The tensile strength and impact toughness of tungsten carbide cemented carbide are very poor. Therefore, when manufacturing high-pressure nozzles, it is necessary to consider improving the strength of the nozzle from the nozzle structure. The most useful method now is to apply pre-pressure to the cemented carbide, that is, insert a sleeve outside the cemented carbide nozzle body to improve the tensile strength and prevent cracking during use. When inserting the sleeve, a satisfactory interference cooperation should be selected to ensure that the nozzle body has a satisfactory prestress.

Abrasive water jet nozzles have always puzzled the water jet industry in China for a long time. So far, the planning and service life of abrasive jet nozzles for incision have not yet reached a satisfactory level. However, the theory of liquid-solid two-phase jet-abrasive jet lacks certain research, and further research is needed for the mixing mechanism of abrasive and water. All of this awaits further research on this aspect by Chinese engineers and technicians. Zhihui nozzle