Nozzles for water jet cutting

he waterjet technology was born in the United States in the early 1970s. It is proud that the founder of this technology is Chinese. However, before the 1990s, its applied technical knowledge was mastered by a few developed countries in Europe and America, and China could only spend a lot of money to introduce it from abroad. The vast majority of enterprises and researchers in research institutes can not experience the shock brought by this cold cutting process, and even don't know what water jet is.

The nozzle of abrasive robot water jet cutting machine is one of the important components in the cutting system. Its structure, working performance and service life directly affect the cutting quality and production cost of the workpiece. It is worth noting that according to different cutting processes, in fact, the nozzle can be divided into pure water cutting nozzle and abrasive cutting nozzle.

In fact, the pure water jet cutting nozzle is used to cut non-metallic soft materials with low density and low hardness. The diameter range of the inner hole of the nozzle is Φ 0.08-0.5mm。

Abrasive cutting nozzle is used to cut hard materials with high density and high hardness. In fact, when ultra-high pressure water is sprayed at high speed from the nozzle hole, a negative pressure vacuum will be formed. Under the action of negative pressure, the abrasive will be sucked into the nozzle through the sand inlet, that is, after mixing with high-pressure water in the mixing chamber, a sand jet will be formed. It is worth noting that the diameter range of nozzle hole is Φ 0.5-1.65mm。

When cutting the workpiece, the nozzle is subjected to great liquid internal pressure, that is, the ultra-high pressure water jet cutting equipment and the high-speed grinding effect of abrasive (using abrasive high-pressure water cutting), which requires that the material of the reconstructed nozzle should have excellent wear resistance, corrosion resistance and high comprehensive mechanical properties. It is worth noting that sapphire, ruby, cemented carbide and diamond are usually used. In other words, considering the factors of cost and manufacturing, gem materials are the most widely used.

There are many factors affecting the service life of the nozzle. It is worth noting that in addition to the nozzle structure, materials, manufacturing, assembly, water pressure and abrasive types, it will actually improve the filtration accuracy and treatment quality of the water medium, that is to say, it will help to improve the service life of the nozzle. Generally, the pH value of water is 6-8 and finely filtered to 0.1 μ Below M. In addition, choosing the appropriate abrasive type and particle size is also very important to improve the service life of the nozzle.